Slide 1

UNIT: Nomenclature
TOPIC: Covalent and Polyatomic Compounds
Objectives: Lesson 2 of 3
• You will learn what a Covalent Compound is
• You will learn how to write the formulas and names for Covalent
Compounds
• You will learn and hopefully memorize the most common
polyatomic ions
• You will also learn how to write formulas and names of polyatomic
compounds

Quickwrite
In 1-2 sentences answer one of the questions below:
• Consider the Compound CO2, how is this compound
different from NaCl (hint: look at their location on the periodic
table)???

• Why do you think we use prefixes such as “tri-” on
words like triceratops, tricycle or tripod?

Covalent Compounds

•• Earlier
learned
about
Notice,we
that
the electrons
Ionic Compounds which
are not
transferred,
form
between
cationsBUT,
instead,metals)
they are
shared
(usually
and
anions
(usually
a nonbetween
the two
atoms
metals)
•• Covalent
As a result,
Covalent
Compounds
Compounds
DOorNOT
have
form
when two
more
non-metal
elements
charges like
Ionic
share
electrons
Compounds
• Recall that Hydrogen is
• classified
Therefore,
use a
aswe
a non-metal
on
the periodic
table
completely
different
• The
simplest
covalent
naming
system
when
compound is Hydrogen
writing
gas
or H2their chemical

formulas and names

H2 - Covalent Compound

Cations+

(usually metals)

-

-

+

What is a Covalent Compound?
• A compound formed between two non-metals
that involves the sharing of electrons
• Example: CO, Carbon Monoxide

Covalent Compounds:
• When naming covalent compounds there are certain steps you must follow
• These steps will help you throughout this unit and the rest of the course:

1. The first element in the formula is named first,
and the full element name is used
2. The 2nd element is named as though it were an anion (add –ide)
3. Prefixes (mono- 1, di- 2, tri- 3) are used to denote
the numbers of atoms

4. The prefix mono- is never used for naming the first element

Prefixes
Prefix

Example

mono- (one)

CO

- carbon monoxide

di- (two)

CO2 - carbon dioxide

tri- (three)

N2O3 - dinitrogen trioxide

tetra- (four)

CCl4 - carbon tetrachloride

penta- (five)

N2O5 - dinitrogen pentoxide

hexa- (six)

UF6 - uranium hexafluoride

Covalent Compounds:
• Write the name for the covalent compound CO Carbon Monoxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Carbon” for Carbon Monoxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in CO is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: Since there is 1 oxygen atom we would use the prefix mono- for Monoxide
4. The prefix mono- is never used for naming the first element
For Example: CO is called Carbon Monoxide NOT Monocarbon Monoxide

Covalent Compounds:
• Write the name for the covalent compound SO3
Sulfur Trioxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Sulfur” for Sulfur Trioxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in SO3 is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: Since there are 3 oxygen atoms we would use the prefix tri- for Trioxide
4. The prefix mono- is never used for naming the first element
For Example: SO3 is called Sulfur Trioxide NOT Monosulfur Trioxide

Covalent Compounds:
• Write the name for the covalent compound
N2O5 - Dinitrogen Pentaoxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Nitrogen” for Dinitrogen Pentaoxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in N2O5 is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: there are 5 oxygen atoms so we would use the prefix penta- for Pentaoxide
4. The prefix mono- is never used for naming the first element
For Example: Since their are 2 nitrogen atoms, we use the prefix di- for Dinitrogen

What are the Steps for
Covalent Compounds?
1. The first element in the formula is named first, and the full
element name is used
2. The 2nd element is named as though it were an anion
3. Prefixes are used to denote the numbers of atomsmono- 1, di- 2, tri- 3, tetra- 4, penta- 5, hexa- 6
4. The prefix mono- is never used for naming the first element

Practice:

Write the names for the following compounds below:
1) SF6

Answer: Sulfur Hexafluoride

2) PCl5

Answer: Phosphorous Pentachloride

3) N2O4

Answer: Dinitrogen Tetraoxide

4) CCl4

Answer: Carbon Tetrachloride

5) CO2

Answer: Carbon Dioxide

6) NO2

Answer: Nitrogen Dioxide

Practice:

Write the formulas for the following compounds below:
1) Dinitrogen Dioxide

Answer: N2O2

2) Sulfur Trioxide

Answer: SO3

3) Diphosphorous Pentaoxide Answer: P2O5
4) Nitrogen Monoxide

Answer: NO

5) Carbon Tetrafluoride

Answer: CF4

6) Silcon Dioxide

Answer: SiO2

Polyatomic Ions

• Polyatomic Ions are a group of two or more atoms
that have a particular charge to them
+1
• An example would include the ammonium ion

[

+
]

• It is composed of
atom and
atoms which give it a +1 charge
• These ions are assigned special names that you
must memorize!

Polyatomic Ions

• Common Polyatomic Ions:
Name

Formula

Name

Formula

nitrate

NO3-1

chromate

CrO4-2

chlorate

ClO3-1

phospite

PO3-3

sulfate

SO4-2

phosphate

PO4-3

carbonate

CO3-2

acetate

C2H3O2-1

hydroxide

OH -1

cyanide

CN-1

ammonium

NH4+1

sulfite

SO3-2

What are Polyatomic Ions?
• A group of two or more atoms that have a
particular charge to them
• No naming rules exist, you must memorize
their names and charge
• Polyatomic Ions
nitrate
NO
chromate
CrO
ClO
phospite
PO
you must memorize: chlorate
sulfate
SO
phosphate PO
Name

Formula

Name

Formula

carbonate

-1
3
-1
3
-2
4
CO3-2

acetate

C2H3O2-1

hydroxide

OH -1

cyanide

CN-1

sulfite

SO3-2

ammonium NH4+1

-2
4
-3
3
-3
4

Practice:

Write the formula and charge for each polyatomic ion
below:
1) hydroxide

Answer: OH-

2) nitrate

Answer: NO3-

3) phosphate

Answer: PO4-3

4) sulfate

Answer: SO4-2

Ionic Compounds with Polyatomic Ions
• Naming ionic compounds that contain polyatomic
ions is very similar to naming ionic compounds
• For example, the compound NaOH contains the
cation, Sodium (Na+1) and the polyatomic ion
hydroxide (OH-1)
• Remember, when Ionic compounds come together,
their charges must always be neutral or ZERO
• Just like ionic compounds, we write the cation first
and the anion second; giving us the compound
Sodium Hydroxide--NaOH

Ionic Compounds with Polyatomic Ions
• Let us look at the compound ammonium nitrate
NH4NO3 (a very explosive chemical)
• Ammonium Nitrate is made up of 2 polyatomic
ions Ammonium (NH4+ ) & Nitrate (NO3-)
• When two polyatomic ions come together, a
neutral compound NH4NO3 forms between them
• Notice, the cation is named first, and anion
second

Ionic Compounds with Polyatomic Ions
• Consider Silver (I) Nitrate: AgNO3
• The Silver (Ag+1) cation comes first, and the polyatomic
anion Nitrate (NO3-1) comes second
• Just like in ionic compounds, the charges need to be
neutral
• The Silver cation Ag+ with a plus one charge is balanced
by the negatively charged polyatomic ion NO3-1 with a
negative one charge
• It is important to realize that because Silver (Ag) is a
transition metal it takes on multiple charges, therefore we
still use roman numerals to illustrate charge
• Therefore we write: Silver (I) Nitrate

Ionic Compounds with Polyatomic Ions
• Consider one more compound: Mg(OH)2
• The Mg+2 cation comes first, and the negative polyatomic
OH- anion comes second
• Just like in ionic compounds, the charges need to be
neutral
• Mg+2 needs be balanced by 2 negatively charged
polyatomic ions OH( )2 when more than one polyatomic
• In the case of Mg(OH)
ion exists, we put PARENTHESIS around them
• By putting parenthesis around (OH)2 and a subscript of 2,
this tells us we have 2 oxygen atoms and 2 hydrogen
atoms

What are Ionic Compounds
with Polyatomic Ions?
• Neutrally charged Compounds that contain a
polyatomic ion
• When more than one polyatomic ion exists in a
compound we put parenthesis around them
• Ex: Mg(OH)2 & AgNO3

Practice:

Write the names for the following compounds below:
1) NaOH

Answer: Sodium Hydroxide

2) Ba(OH)2

Answer: Barium Hydroxide

3) NH4Cl

Answer: Ammonium Chloride

4) AgNO3

Answer: Silver (I) Nitrate

5) CaCO3

Answer: Calcium Carbonate

6) Mg(NO3)2

Answer: Magnesium Nitrate

For assistance,
look back at the
rules for naming
Ionic Compounds

Practice:

Write the formulas for the following compounds below:
1) Calcium Hydroxide

Answer: Ca(OH)2

2) Magnesium Sulfate

Answer: MgSO4

3) Aluminum Phosphate

Answer: AlPO4

4) Ammonium Hydroxide

Answer: NH4OH

5) Iron (II) Sulfate

Answer: FeSO4

6) Calcium Phosphate

Answer: Ca3(PO4)2

For assistance,
look back at the
rules for naming
Ionic Compounds

Summarize:
(you can always write you own)
• Explain the difference between a Ionic Compound and a Covalent
Compound:
• What numbers do the following prefixes represent: tetra-, tri-, penta- ,
hexa• Write down the polyatomic ions you need to memorize, arrange them in
order according to their charge:
• Explain how we name polyatomic compounds:
• Explain how we write formulas for polyatomic compounds:
• What do we do if more than one polyatomic ion is present in a
compound?


Slide 2

UNIT: Nomenclature
TOPIC: Covalent and Polyatomic Compounds
Objectives: Lesson 2 of 3
• You will learn what a Covalent Compound is
• You will learn how to write the formulas and names for Covalent
Compounds
• You will learn and hopefully memorize the most common
polyatomic ions
• You will also learn how to write formulas and names of polyatomic
compounds

Quickwrite
In 1-2 sentences answer one of the questions below:
• Consider the Compound CO2, how is this compound
different from NaCl (hint: look at their location on the periodic
table)???

• Why do you think we use prefixes such as “tri-” on
words like triceratops, tricycle or tripod?

Covalent Compounds

•• Earlier
learned
about
Notice,we
that
the electrons
Ionic Compounds which
are not
transferred,
form
between
cationsBUT,
instead,metals)
they are
shared
(usually
and
anions
(usually
a nonbetween
the two
atoms
metals)
•• Covalent
As a result,
Covalent
Compounds
Compounds
DOorNOT
have
form
when two
more
non-metal
elements
charges like
Ionic
share
electrons
Compounds
• Recall that Hydrogen is
• classified
Therefore,
use a
aswe
a non-metal
on
the periodic
table
completely
different
• The
simplest
covalent
naming
system
when
compound is Hydrogen
writing
gas
or H2their chemical

formulas and names

H2 - Covalent Compound

Cations+

(usually metals)

-

-

+

What is a Covalent Compound?
• A compound formed between two non-metals
that involves the sharing of electrons
• Example: CO, Carbon Monoxide

Covalent Compounds:
• When naming covalent compounds there are certain steps you must follow
• These steps will help you throughout this unit and the rest of the course:

1. The first element in the formula is named first,
and the full element name is used
2. The 2nd element is named as though it were an anion (add –ide)
3. Prefixes (mono- 1, di- 2, tri- 3) are used to denote
the numbers of atoms

4. The prefix mono- is never used for naming the first element

Prefixes
Prefix

Example

mono- (one)

CO

- carbon monoxide

di- (two)

CO2 - carbon dioxide

tri- (three)

N2O3 - dinitrogen trioxide

tetra- (four)

CCl4 - carbon tetrachloride

penta- (five)

N2O5 - dinitrogen pentoxide

hexa- (six)

UF6 - uranium hexafluoride

Covalent Compounds:
• Write the name for the covalent compound CO Carbon Monoxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Carbon” for Carbon Monoxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in CO is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: Since there is 1 oxygen atom we would use the prefix mono- for Monoxide
4. The prefix mono- is never used for naming the first element
For Example: CO is called Carbon Monoxide NOT Monocarbon Monoxide

Covalent Compounds:
• Write the name for the covalent compound SO3
Sulfur Trioxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Sulfur” for Sulfur Trioxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in SO3 is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: Since there are 3 oxygen atoms we would use the prefix tri- for Trioxide
4. The prefix mono- is never used for naming the first element
For Example: SO3 is called Sulfur Trioxide NOT Monosulfur Trioxide

Covalent Compounds:
• Write the name for the covalent compound
N2O5 - Dinitrogen Pentaoxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Nitrogen” for Dinitrogen Pentaoxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in N2O5 is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: there are 5 oxygen atoms so we would use the prefix penta- for Pentaoxide
4. The prefix mono- is never used for naming the first element
For Example: Since their are 2 nitrogen atoms, we use the prefix di- for Dinitrogen

What are the Steps for
Covalent Compounds?
1. The first element in the formula is named first, and the full
element name is used
2. The 2nd element is named as though it were an anion
3. Prefixes are used to denote the numbers of atomsmono- 1, di- 2, tri- 3, tetra- 4, penta- 5, hexa- 6
4. The prefix mono- is never used for naming the first element

Practice:

Write the names for the following compounds below:
1) SF6

Answer: Sulfur Hexafluoride

2) PCl5

Answer: Phosphorous Pentachloride

3) N2O4

Answer: Dinitrogen Tetraoxide

4) CCl4

Answer: Carbon Tetrachloride

5) CO2

Answer: Carbon Dioxide

6) NO2

Answer: Nitrogen Dioxide

Practice:

Write the formulas for the following compounds below:
1) Dinitrogen Dioxide

Answer: N2O2

2) Sulfur Trioxide

Answer: SO3

3) Diphosphorous Pentaoxide Answer: P2O5
4) Nitrogen Monoxide

Answer: NO

5) Carbon Tetrafluoride

Answer: CF4

6) Silcon Dioxide

Answer: SiO2

Polyatomic Ions

• Polyatomic Ions are a group of two or more atoms
that have a particular charge to them
+1
• An example would include the ammonium ion

[

+
]

• It is composed of
atom and
atoms which give it a +1 charge
• These ions are assigned special names that you
must memorize!

Polyatomic Ions

• Common Polyatomic Ions:
Name

Formula

Name

Formula

nitrate

NO3-1

chromate

CrO4-2

chlorate

ClO3-1

phospite

PO3-3

sulfate

SO4-2

phosphate

PO4-3

carbonate

CO3-2

acetate

C2H3O2-1

hydroxide

OH -1

cyanide

CN-1

ammonium

NH4+1

sulfite

SO3-2

What are Polyatomic Ions?
• A group of two or more atoms that have a
particular charge to them
• No naming rules exist, you must memorize
their names and charge
• Polyatomic Ions
nitrate
NO
chromate
CrO
ClO
phospite
PO
you must memorize: chlorate
sulfate
SO
phosphate PO
Name

Formula

Name

Formula

carbonate

-1
3
-1
3
-2
4
CO3-2

acetate

C2H3O2-1

hydroxide

OH -1

cyanide

CN-1

sulfite

SO3-2

ammonium NH4+1

-2
4
-3
3
-3
4

Practice:

Write the formula and charge for each polyatomic ion
below:
1) hydroxide

Answer: OH-

2) nitrate

Answer: NO3-

3) phosphate

Answer: PO4-3

4) sulfate

Answer: SO4-2

Ionic Compounds with Polyatomic Ions
• Naming ionic compounds that contain polyatomic
ions is very similar to naming ionic compounds
• For example, the compound NaOH contains the
cation, Sodium (Na+1) and the polyatomic ion
hydroxide (OH-1)
• Remember, when Ionic compounds come together,
their charges must always be neutral or ZERO
• Just like ionic compounds, we write the cation first
and the anion second; giving us the compound
Sodium Hydroxide--NaOH

Ionic Compounds with Polyatomic Ions
• Let us look at the compound ammonium nitrate
NH4NO3 (a very explosive chemical)
• Ammonium Nitrate is made up of 2 polyatomic
ions Ammonium (NH4+ ) & Nitrate (NO3-)
• When two polyatomic ions come together, a
neutral compound NH4NO3 forms between them
• Notice, the cation is named first, and anion
second

Ionic Compounds with Polyatomic Ions
• Consider Silver (I) Nitrate: AgNO3
• The Silver (Ag+1) cation comes first, and the polyatomic
anion Nitrate (NO3-1) comes second
• Just like in ionic compounds, the charges need to be
neutral
• The Silver cation Ag+ with a plus one charge is balanced
by the negatively charged polyatomic ion NO3-1 with a
negative one charge
• It is important to realize that because Silver (Ag) is a
transition metal it takes on multiple charges, therefore we
still use roman numerals to illustrate charge
• Therefore we write: Silver (I) Nitrate

Ionic Compounds with Polyatomic Ions
• Consider one more compound: Mg(OH)2
• The Mg+2 cation comes first, and the negative polyatomic
OH- anion comes second
• Just like in ionic compounds, the charges need to be
neutral
• Mg+2 needs be balanced by 2 negatively charged
polyatomic ions OH( )2 when more than one polyatomic
• In the case of Mg(OH)
ion exists, we put PARENTHESIS around them
• By putting parenthesis around (OH)2 and a subscript of 2,
this tells us we have 2 oxygen atoms and 2 hydrogen
atoms

What are Ionic Compounds
with Polyatomic Ions?
• Neutrally charged Compounds that contain a
polyatomic ion
• When more than one polyatomic ion exists in a
compound we put parenthesis around them
• Ex: Mg(OH)2 & AgNO3

Practice:

Write the names for the following compounds below:
1) NaOH

Answer: Sodium Hydroxide

2) Ba(OH)2

Answer: Barium Hydroxide

3) NH4Cl

Answer: Ammonium Chloride

4) AgNO3

Answer: Silver (I) Nitrate

5) CaCO3

Answer: Calcium Carbonate

6) Mg(NO3)2

Answer: Magnesium Nitrate

For assistance,
look back at the
rules for naming
Ionic Compounds

Practice:

Write the formulas for the following compounds below:
1) Calcium Hydroxide

Answer: Ca(OH)2

2) Magnesium Sulfate

Answer: MgSO4

3) Aluminum Phosphate

Answer: AlPO4

4) Ammonium Hydroxide

Answer: NH4OH

5) Iron (II) Sulfate

Answer: FeSO4

6) Calcium Phosphate

Answer: Ca3(PO4)2

For assistance,
look back at the
rules for naming
Ionic Compounds

Summarize:
(you can always write you own)
• Explain the difference between a Ionic Compound and a Covalent
Compound:
• What numbers do the following prefixes represent: tetra-, tri-, penta- ,
hexa• Write down the polyatomic ions you need to memorize, arrange them in
order according to their charge:
• Explain how we name polyatomic compounds:
• Explain how we write formulas for polyatomic compounds:
• What do we do if more than one polyatomic ion is present in a
compound?


Slide 3

UNIT: Nomenclature
TOPIC: Covalent and Polyatomic Compounds
Objectives: Lesson 2 of 3
• You will learn what a Covalent Compound is
• You will learn how to write the formulas and names for Covalent
Compounds
• You will learn and hopefully memorize the most common
polyatomic ions
• You will also learn how to write formulas and names of polyatomic
compounds

Quickwrite
In 1-2 sentences answer one of the questions below:
• Consider the Compound CO2, how is this compound
different from NaCl (hint: look at their location on the periodic
table)???

• Why do you think we use prefixes such as “tri-” on
words like triceratops, tricycle or tripod?

Covalent Compounds

•• Earlier
learned
about
Notice,we
that
the electrons
Ionic Compounds which
are not
transferred,
form
between
cationsBUT,
instead,metals)
they are
shared
(usually
and
anions
(usually
a nonbetween
the two
atoms
metals)
•• Covalent
As a result,
Covalent
Compounds
Compounds
DOorNOT
have
form
when two
more
non-metal
elements
charges like
Ionic
share
electrons
Compounds
• Recall that Hydrogen is
• classified
Therefore,
use a
aswe
a non-metal
on
the periodic
table
completely
different
• The
simplest
covalent
naming
system
when
compound is Hydrogen
writing
gas
or H2their chemical

formulas and names

H2 - Covalent Compound

Cations+

(usually metals)

-

-

+

What is a Covalent Compound?
• A compound formed between two non-metals
that involves the sharing of electrons
• Example: CO, Carbon Monoxide

Covalent Compounds:
• When naming covalent compounds there are certain steps you must follow
• These steps will help you throughout this unit and the rest of the course:

1. The first element in the formula is named first,
and the full element name is used
2. The 2nd element is named as though it were an anion (add –ide)
3. Prefixes (mono- 1, di- 2, tri- 3) are used to denote
the numbers of atoms

4. The prefix mono- is never used for naming the first element

Prefixes
Prefix

Example

mono- (one)

CO

- carbon monoxide

di- (two)

CO2 - carbon dioxide

tri- (three)

N2O3 - dinitrogen trioxide

tetra- (four)

CCl4 - carbon tetrachloride

penta- (five)

N2O5 - dinitrogen pentoxide

hexa- (six)

UF6 - uranium hexafluoride

Covalent Compounds:
• Write the name for the covalent compound CO Carbon Monoxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Carbon” for Carbon Monoxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in CO is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: Since there is 1 oxygen atom we would use the prefix mono- for Monoxide
4. The prefix mono- is never used for naming the first element
For Example: CO is called Carbon Monoxide NOT Monocarbon Monoxide

Covalent Compounds:
• Write the name for the covalent compound SO3
Sulfur Trioxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Sulfur” for Sulfur Trioxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in SO3 is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: Since there are 3 oxygen atoms we would use the prefix tri- for Trioxide
4. The prefix mono- is never used for naming the first element
For Example: SO3 is called Sulfur Trioxide NOT Monosulfur Trioxide

Covalent Compounds:
• Write the name for the covalent compound
N2O5 - Dinitrogen Pentaoxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Nitrogen” for Dinitrogen Pentaoxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in N2O5 is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: there are 5 oxygen atoms so we would use the prefix penta- for Pentaoxide
4. The prefix mono- is never used for naming the first element
For Example: Since their are 2 nitrogen atoms, we use the prefix di- for Dinitrogen

What are the Steps for
Covalent Compounds?
1. The first element in the formula is named first, and the full
element name is used
2. The 2nd element is named as though it were an anion
3. Prefixes are used to denote the numbers of atomsmono- 1, di- 2, tri- 3, tetra- 4, penta- 5, hexa- 6
4. The prefix mono- is never used for naming the first element

Practice:

Write the names for the following compounds below:
1) SF6

Answer: Sulfur Hexafluoride

2) PCl5

Answer: Phosphorous Pentachloride

3) N2O4

Answer: Dinitrogen Tetraoxide

4) CCl4

Answer: Carbon Tetrachloride

5) CO2

Answer: Carbon Dioxide

6) NO2

Answer: Nitrogen Dioxide

Practice:

Write the formulas for the following compounds below:
1) Dinitrogen Dioxide

Answer: N2O2

2) Sulfur Trioxide

Answer: SO3

3) Diphosphorous Pentaoxide Answer: P2O5
4) Nitrogen Monoxide

Answer: NO

5) Carbon Tetrafluoride

Answer: CF4

6) Silcon Dioxide

Answer: SiO2

Polyatomic Ions

• Polyatomic Ions are a group of two or more atoms
that have a particular charge to them
+1
• An example would include the ammonium ion

[

+
]

• It is composed of
atom and
atoms which give it a +1 charge
• These ions are assigned special names that you
must memorize!

Polyatomic Ions

• Common Polyatomic Ions:
Name

Formula

Name

Formula

nitrate

NO3-1

chromate

CrO4-2

chlorate

ClO3-1

phospite

PO3-3

sulfate

SO4-2

phosphate

PO4-3

carbonate

CO3-2

acetate

C2H3O2-1

hydroxide

OH -1

cyanide

CN-1

ammonium

NH4+1

sulfite

SO3-2

What are Polyatomic Ions?
• A group of two or more atoms that have a
particular charge to them
• No naming rules exist, you must memorize
their names and charge
• Polyatomic Ions
nitrate
NO
chromate
CrO
ClO
phospite
PO
you must memorize: chlorate
sulfate
SO
phosphate PO
Name

Formula

Name

Formula

carbonate

-1
3
-1
3
-2
4
CO3-2

acetate

C2H3O2-1

hydroxide

OH -1

cyanide

CN-1

sulfite

SO3-2

ammonium NH4+1

-2
4
-3
3
-3
4

Practice:

Write the formula and charge for each polyatomic ion
below:
1) hydroxide

Answer: OH-

2) nitrate

Answer: NO3-

3) phosphate

Answer: PO4-3

4) sulfate

Answer: SO4-2

Ionic Compounds with Polyatomic Ions
• Naming ionic compounds that contain polyatomic
ions is very similar to naming ionic compounds
• For example, the compound NaOH contains the
cation, Sodium (Na+1) and the polyatomic ion
hydroxide (OH-1)
• Remember, when Ionic compounds come together,
their charges must always be neutral or ZERO
• Just like ionic compounds, we write the cation first
and the anion second; giving us the compound
Sodium Hydroxide--NaOH

Ionic Compounds with Polyatomic Ions
• Let us look at the compound ammonium nitrate
NH4NO3 (a very explosive chemical)
• Ammonium Nitrate is made up of 2 polyatomic
ions Ammonium (NH4+ ) & Nitrate (NO3-)
• When two polyatomic ions come together, a
neutral compound NH4NO3 forms between them
• Notice, the cation is named first, and anion
second

Ionic Compounds with Polyatomic Ions
• Consider Silver (I) Nitrate: AgNO3
• The Silver (Ag+1) cation comes first, and the polyatomic
anion Nitrate (NO3-1) comes second
• Just like in ionic compounds, the charges need to be
neutral
• The Silver cation Ag+ with a plus one charge is balanced
by the negatively charged polyatomic ion NO3-1 with a
negative one charge
• It is important to realize that because Silver (Ag) is a
transition metal it takes on multiple charges, therefore we
still use roman numerals to illustrate charge
• Therefore we write: Silver (I) Nitrate

Ionic Compounds with Polyatomic Ions
• Consider one more compound: Mg(OH)2
• The Mg+2 cation comes first, and the negative polyatomic
OH- anion comes second
• Just like in ionic compounds, the charges need to be
neutral
• Mg+2 needs be balanced by 2 negatively charged
polyatomic ions OH( )2 when more than one polyatomic
• In the case of Mg(OH)
ion exists, we put PARENTHESIS around them
• By putting parenthesis around (OH)2 and a subscript of 2,
this tells us we have 2 oxygen atoms and 2 hydrogen
atoms

What are Ionic Compounds
with Polyatomic Ions?
• Neutrally charged Compounds that contain a
polyatomic ion
• When more than one polyatomic ion exists in a
compound we put parenthesis around them
• Ex: Mg(OH)2 & AgNO3

Practice:

Write the names for the following compounds below:
1) NaOH

Answer: Sodium Hydroxide

2) Ba(OH)2

Answer: Barium Hydroxide

3) NH4Cl

Answer: Ammonium Chloride

4) AgNO3

Answer: Silver (I) Nitrate

5) CaCO3

Answer: Calcium Carbonate

6) Mg(NO3)2

Answer: Magnesium Nitrate

For assistance,
look back at the
rules for naming
Ionic Compounds

Practice:

Write the formulas for the following compounds below:
1) Calcium Hydroxide

Answer: Ca(OH)2

2) Magnesium Sulfate

Answer: MgSO4

3) Aluminum Phosphate

Answer: AlPO4

4) Ammonium Hydroxide

Answer: NH4OH

5) Iron (II) Sulfate

Answer: FeSO4

6) Calcium Phosphate

Answer: Ca3(PO4)2

For assistance,
look back at the
rules for naming
Ionic Compounds

Summarize:
(you can always write you own)
• Explain the difference between a Ionic Compound and a Covalent
Compound:
• What numbers do the following prefixes represent: tetra-, tri-, penta- ,
hexa• Write down the polyatomic ions you need to memorize, arrange them in
order according to their charge:
• Explain how we name polyatomic compounds:
• Explain how we write formulas for polyatomic compounds:
• What do we do if more than one polyatomic ion is present in a
compound?


Slide 4

UNIT: Nomenclature
TOPIC: Covalent and Polyatomic Compounds
Objectives: Lesson 2 of 3
• You will learn what a Covalent Compound is
• You will learn how to write the formulas and names for Covalent
Compounds
• You will learn and hopefully memorize the most common
polyatomic ions
• You will also learn how to write formulas and names of polyatomic
compounds

Quickwrite
In 1-2 sentences answer one of the questions below:
• Consider the Compound CO2, how is this compound
different from NaCl (hint: look at their location on the periodic
table)???

• Why do you think we use prefixes such as “tri-” on
words like triceratops, tricycle or tripod?

Covalent Compounds

•• Earlier
learned
about
Notice,we
that
the electrons
Ionic Compounds which
are not
transferred,
form
between
cationsBUT,
instead,metals)
they are
shared
(usually
and
anions
(usually
a nonbetween
the two
atoms
metals)
•• Covalent
As a result,
Covalent
Compounds
Compounds
DOorNOT
have
form
when two
more
non-metal
elements
charges like
Ionic
share
electrons
Compounds
• Recall that Hydrogen is
• classified
Therefore,
use a
aswe
a non-metal
on
the periodic
table
completely
different
• The
simplest
covalent
naming
system
when
compound is Hydrogen
writing
gas
or H2their chemical

formulas and names

H2 - Covalent Compound

Cations+

(usually metals)

-

-

+

What is a Covalent Compound?
• A compound formed between two non-metals
that involves the sharing of electrons
• Example: CO, Carbon Monoxide

Covalent Compounds:
• When naming covalent compounds there are certain steps you must follow
• These steps will help you throughout this unit and the rest of the course:

1. The first element in the formula is named first,
and the full element name is used
2. The 2nd element is named as though it were an anion (add –ide)
3. Prefixes (mono- 1, di- 2, tri- 3) are used to denote
the numbers of atoms

4. The prefix mono- is never used for naming the first element

Prefixes
Prefix

Example

mono- (one)

CO

- carbon monoxide

di- (two)

CO2 - carbon dioxide

tri- (three)

N2O3 - dinitrogen trioxide

tetra- (four)

CCl4 - carbon tetrachloride

penta- (five)

N2O5 - dinitrogen pentoxide

hexa- (six)

UF6 - uranium hexafluoride

Covalent Compounds:
• Write the name for the covalent compound CO Carbon Monoxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Carbon” for Carbon Monoxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in CO is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: Since there is 1 oxygen atom we would use the prefix mono- for Monoxide
4. The prefix mono- is never used for naming the first element
For Example: CO is called Carbon Monoxide NOT Monocarbon Monoxide

Covalent Compounds:
• Write the name for the covalent compound SO3
Sulfur Trioxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Sulfur” for Sulfur Trioxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in SO3 is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: Since there are 3 oxygen atoms we would use the prefix tri- for Trioxide
4. The prefix mono- is never used for naming the first element
For Example: SO3 is called Sulfur Trioxide NOT Monosulfur Trioxide

Covalent Compounds:
• Write the name for the covalent compound
N2O5 - Dinitrogen Pentaoxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Nitrogen” for Dinitrogen Pentaoxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in N2O5 is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: there are 5 oxygen atoms so we would use the prefix penta- for Pentaoxide
4. The prefix mono- is never used for naming the first element
For Example: Since their are 2 nitrogen atoms, we use the prefix di- for Dinitrogen

What are the Steps for
Covalent Compounds?
1. The first element in the formula is named first, and the full
element name is used
2. The 2nd element is named as though it were an anion
3. Prefixes are used to denote the numbers of atomsmono- 1, di- 2, tri- 3, tetra- 4, penta- 5, hexa- 6
4. The prefix mono- is never used for naming the first element

Practice:

Write the names for the following compounds below:
1) SF6

Answer: Sulfur Hexafluoride

2) PCl5

Answer: Phosphorous Pentachloride

3) N2O4

Answer: Dinitrogen Tetraoxide

4) CCl4

Answer: Carbon Tetrachloride

5) CO2

Answer: Carbon Dioxide

6) NO2

Answer: Nitrogen Dioxide

Practice:

Write the formulas for the following compounds below:
1) Dinitrogen Dioxide

Answer: N2O2

2) Sulfur Trioxide

Answer: SO3

3) Diphosphorous Pentaoxide Answer: P2O5
4) Nitrogen Monoxide

Answer: NO

5) Carbon Tetrafluoride

Answer: CF4

6) Silcon Dioxide

Answer: SiO2

Polyatomic Ions

• Polyatomic Ions are a group of two or more atoms
that have a particular charge to them
+1
• An example would include the ammonium ion

[

+
]

• It is composed of
atom and
atoms which give it a +1 charge
• These ions are assigned special names that you
must memorize!

Polyatomic Ions

• Common Polyatomic Ions:
Name

Formula

Name

Formula

nitrate

NO3-1

chromate

CrO4-2

chlorate

ClO3-1

phospite

PO3-3

sulfate

SO4-2

phosphate

PO4-3

carbonate

CO3-2

acetate

C2H3O2-1

hydroxide

OH -1

cyanide

CN-1

ammonium

NH4+1

sulfite

SO3-2

What are Polyatomic Ions?
• A group of two or more atoms that have a
particular charge to them
• No naming rules exist, you must memorize
their names and charge
• Polyatomic Ions
nitrate
NO
chromate
CrO
ClO
phospite
PO
you must memorize: chlorate
sulfate
SO
phosphate PO
Name

Formula

Name

Formula

carbonate

-1
3
-1
3
-2
4
CO3-2

acetate

C2H3O2-1

hydroxide

OH -1

cyanide

CN-1

sulfite

SO3-2

ammonium NH4+1

-2
4
-3
3
-3
4

Practice:

Write the formula and charge for each polyatomic ion
below:
1) hydroxide

Answer: OH-

2) nitrate

Answer: NO3-

3) phosphate

Answer: PO4-3

4) sulfate

Answer: SO4-2

Ionic Compounds with Polyatomic Ions
• Naming ionic compounds that contain polyatomic
ions is very similar to naming ionic compounds
• For example, the compound NaOH contains the
cation, Sodium (Na+1) and the polyatomic ion
hydroxide (OH-1)
• Remember, when Ionic compounds come together,
their charges must always be neutral or ZERO
• Just like ionic compounds, we write the cation first
and the anion second; giving us the compound
Sodium Hydroxide--NaOH

Ionic Compounds with Polyatomic Ions
• Let us look at the compound ammonium nitrate
NH4NO3 (a very explosive chemical)
• Ammonium Nitrate is made up of 2 polyatomic
ions Ammonium (NH4+ ) & Nitrate (NO3-)
• When two polyatomic ions come together, a
neutral compound NH4NO3 forms between them
• Notice, the cation is named first, and anion
second

Ionic Compounds with Polyatomic Ions
• Consider Silver (I) Nitrate: AgNO3
• The Silver (Ag+1) cation comes first, and the polyatomic
anion Nitrate (NO3-1) comes second
• Just like in ionic compounds, the charges need to be
neutral
• The Silver cation Ag+ with a plus one charge is balanced
by the negatively charged polyatomic ion NO3-1 with a
negative one charge
• It is important to realize that because Silver (Ag) is a
transition metal it takes on multiple charges, therefore we
still use roman numerals to illustrate charge
• Therefore we write: Silver (I) Nitrate

Ionic Compounds with Polyatomic Ions
• Consider one more compound: Mg(OH)2
• The Mg+2 cation comes first, and the negative polyatomic
OH- anion comes second
• Just like in ionic compounds, the charges need to be
neutral
• Mg+2 needs be balanced by 2 negatively charged
polyatomic ions OH( )2 when more than one polyatomic
• In the case of Mg(OH)
ion exists, we put PARENTHESIS around them
• By putting parenthesis around (OH)2 and a subscript of 2,
this tells us we have 2 oxygen atoms and 2 hydrogen
atoms

What are Ionic Compounds
with Polyatomic Ions?
• Neutrally charged Compounds that contain a
polyatomic ion
• When more than one polyatomic ion exists in a
compound we put parenthesis around them
• Ex: Mg(OH)2 & AgNO3

Practice:

Write the names for the following compounds below:
1) NaOH

Answer: Sodium Hydroxide

2) Ba(OH)2

Answer: Barium Hydroxide

3) NH4Cl

Answer: Ammonium Chloride

4) AgNO3

Answer: Silver (I) Nitrate

5) CaCO3

Answer: Calcium Carbonate

6) Mg(NO3)2

Answer: Magnesium Nitrate

For assistance,
look back at the
rules for naming
Ionic Compounds

Practice:

Write the formulas for the following compounds below:
1) Calcium Hydroxide

Answer: Ca(OH)2

2) Magnesium Sulfate

Answer: MgSO4

3) Aluminum Phosphate

Answer: AlPO4

4) Ammonium Hydroxide

Answer: NH4OH

5) Iron (II) Sulfate

Answer: FeSO4

6) Calcium Phosphate

Answer: Ca3(PO4)2

For assistance,
look back at the
rules for naming
Ionic Compounds

Summarize:
(you can always write you own)
• Explain the difference between a Ionic Compound and a Covalent
Compound:
• What numbers do the following prefixes represent: tetra-, tri-, penta- ,
hexa• Write down the polyatomic ions you need to memorize, arrange them in
order according to their charge:
• Explain how we name polyatomic compounds:
• Explain how we write formulas for polyatomic compounds:
• What do we do if more than one polyatomic ion is present in a
compound?


Slide 5

UNIT: Nomenclature
TOPIC: Covalent and Polyatomic Compounds
Objectives: Lesson 2 of 3
• You will learn what a Covalent Compound is
• You will learn how to write the formulas and names for Covalent
Compounds
• You will learn and hopefully memorize the most common
polyatomic ions
• You will also learn how to write formulas and names of polyatomic
compounds

Quickwrite
In 1-2 sentences answer one of the questions below:
• Consider the Compound CO2, how is this compound
different from NaCl (hint: look at their location on the periodic
table)???

• Why do you think we use prefixes such as “tri-” on
words like triceratops, tricycle or tripod?

Covalent Compounds

•• Earlier
learned
about
Notice,we
that
the electrons
Ionic Compounds which
are not
transferred,
form
between
cationsBUT,
instead,metals)
they are
shared
(usually
and
anions
(usually
a nonbetween
the two
atoms
metals)
•• Covalent
As a result,
Covalent
Compounds
Compounds
DOorNOT
have
form
when two
more
non-metal
elements
charges like
Ionic
share
electrons
Compounds
• Recall that Hydrogen is
• classified
Therefore,
use a
aswe
a non-metal
on
the periodic
table
completely
different
• The
simplest
covalent
naming
system
when
compound is Hydrogen
writing
gas
or H2their chemical

formulas and names

H2 - Covalent Compound

Cations+

(usually metals)

-

-

+

What is a Covalent Compound?
• A compound formed between two non-metals
that involves the sharing of electrons
• Example: CO, Carbon Monoxide

Covalent Compounds:
• When naming covalent compounds there are certain steps you must follow
• These steps will help you throughout this unit and the rest of the course:

1. The first element in the formula is named first,
and the full element name is used
2. The 2nd element is named as though it were an anion (add –ide)
3. Prefixes (mono- 1, di- 2, tri- 3) are used to denote
the numbers of atoms

4. The prefix mono- is never used for naming the first element

Prefixes
Prefix

Example

mono- (one)

CO

- carbon monoxide

di- (two)

CO2 - carbon dioxide

tri- (three)

N2O3 - dinitrogen trioxide

tetra- (four)

CCl4 - carbon tetrachloride

penta- (five)

N2O5 - dinitrogen pentoxide

hexa- (six)

UF6 - uranium hexafluoride

Covalent Compounds:
• Write the name for the covalent compound CO Carbon Monoxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Carbon” for Carbon Monoxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in CO is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: Since there is 1 oxygen atom we would use the prefix mono- for Monoxide
4. The prefix mono- is never used for naming the first element
For Example: CO is called Carbon Monoxide NOT Monocarbon Monoxide

Covalent Compounds:
• Write the name for the covalent compound SO3
Sulfur Trioxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Sulfur” for Sulfur Trioxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in SO3 is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: Since there are 3 oxygen atoms we would use the prefix tri- for Trioxide
4. The prefix mono- is never used for naming the first element
For Example: SO3 is called Sulfur Trioxide NOT Monosulfur Trioxide

Covalent Compounds:
• Write the name for the covalent compound
N2O5 - Dinitrogen Pentaoxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Nitrogen” for Dinitrogen Pentaoxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in N2O5 is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: there are 5 oxygen atoms so we would use the prefix penta- for Pentaoxide
4. The prefix mono- is never used for naming the first element
For Example: Since their are 2 nitrogen atoms, we use the prefix di- for Dinitrogen

What are the Steps for
Covalent Compounds?
1. The first element in the formula is named first, and the full
element name is used
2. The 2nd element is named as though it were an anion
3. Prefixes are used to denote the numbers of atomsmono- 1, di- 2, tri- 3, tetra- 4, penta- 5, hexa- 6
4. The prefix mono- is never used for naming the first element

Practice:

Write the names for the following compounds below:
1) SF6

Answer: Sulfur Hexafluoride

2) PCl5

Answer: Phosphorous Pentachloride

3) N2O4

Answer: Dinitrogen Tetraoxide

4) CCl4

Answer: Carbon Tetrachloride

5) CO2

Answer: Carbon Dioxide

6) NO2

Answer: Nitrogen Dioxide

Practice:

Write the formulas for the following compounds below:
1) Dinitrogen Dioxide

Answer: N2O2

2) Sulfur Trioxide

Answer: SO3

3) Diphosphorous Pentaoxide Answer: P2O5
4) Nitrogen Monoxide

Answer: NO

5) Carbon Tetrafluoride

Answer: CF4

6) Silcon Dioxide

Answer: SiO2

Polyatomic Ions

• Polyatomic Ions are a group of two or more atoms
that have a particular charge to them
+1
• An example would include the ammonium ion

[

+
]

• It is composed of
atom and
atoms which give it a +1 charge
• These ions are assigned special names that you
must memorize!

Polyatomic Ions

• Common Polyatomic Ions:
Name

Formula

Name

Formula

nitrate

NO3-1

chromate

CrO4-2

chlorate

ClO3-1

phospite

PO3-3

sulfate

SO4-2

phosphate

PO4-3

carbonate

CO3-2

acetate

C2H3O2-1

hydroxide

OH -1

cyanide

CN-1

ammonium

NH4+1

sulfite

SO3-2

What are Polyatomic Ions?
• A group of two or more atoms that have a
particular charge to them
• No naming rules exist, you must memorize
their names and charge
• Polyatomic Ions
nitrate
NO
chromate
CrO
ClO
phospite
PO
you must memorize: chlorate
sulfate
SO
phosphate PO
Name

Formula

Name

Formula

carbonate

-1
3
-1
3
-2
4
CO3-2

acetate

C2H3O2-1

hydroxide

OH -1

cyanide

CN-1

sulfite

SO3-2

ammonium NH4+1

-2
4
-3
3
-3
4

Practice:

Write the formula and charge for each polyatomic ion
below:
1) hydroxide

Answer: OH-

2) nitrate

Answer: NO3-

3) phosphate

Answer: PO4-3

4) sulfate

Answer: SO4-2

Ionic Compounds with Polyatomic Ions
• Naming ionic compounds that contain polyatomic
ions is very similar to naming ionic compounds
• For example, the compound NaOH contains the
cation, Sodium (Na+1) and the polyatomic ion
hydroxide (OH-1)
• Remember, when Ionic compounds come together,
their charges must always be neutral or ZERO
• Just like ionic compounds, we write the cation first
and the anion second; giving us the compound
Sodium Hydroxide--NaOH

Ionic Compounds with Polyatomic Ions
• Let us look at the compound ammonium nitrate
NH4NO3 (a very explosive chemical)
• Ammonium Nitrate is made up of 2 polyatomic
ions Ammonium (NH4+ ) & Nitrate (NO3-)
• When two polyatomic ions come together, a
neutral compound NH4NO3 forms between them
• Notice, the cation is named first, and anion
second

Ionic Compounds with Polyatomic Ions
• Consider Silver (I) Nitrate: AgNO3
• The Silver (Ag+1) cation comes first, and the polyatomic
anion Nitrate (NO3-1) comes second
• Just like in ionic compounds, the charges need to be
neutral
• The Silver cation Ag+ with a plus one charge is balanced
by the negatively charged polyatomic ion NO3-1 with a
negative one charge
• It is important to realize that because Silver (Ag) is a
transition metal it takes on multiple charges, therefore we
still use roman numerals to illustrate charge
• Therefore we write: Silver (I) Nitrate

Ionic Compounds with Polyatomic Ions
• Consider one more compound: Mg(OH)2
• The Mg+2 cation comes first, and the negative polyatomic
OH- anion comes second
• Just like in ionic compounds, the charges need to be
neutral
• Mg+2 needs be balanced by 2 negatively charged
polyatomic ions OH( )2 when more than one polyatomic
• In the case of Mg(OH)
ion exists, we put PARENTHESIS around them
• By putting parenthesis around (OH)2 and a subscript of 2,
this tells us we have 2 oxygen atoms and 2 hydrogen
atoms

What are Ionic Compounds
with Polyatomic Ions?
• Neutrally charged Compounds that contain a
polyatomic ion
• When more than one polyatomic ion exists in a
compound we put parenthesis around them
• Ex: Mg(OH)2 & AgNO3

Practice:

Write the names for the following compounds below:
1) NaOH

Answer: Sodium Hydroxide

2) Ba(OH)2

Answer: Barium Hydroxide

3) NH4Cl

Answer: Ammonium Chloride

4) AgNO3

Answer: Silver (I) Nitrate

5) CaCO3

Answer: Calcium Carbonate

6) Mg(NO3)2

Answer: Magnesium Nitrate

For assistance,
look back at the
rules for naming
Ionic Compounds

Practice:

Write the formulas for the following compounds below:
1) Calcium Hydroxide

Answer: Ca(OH)2

2) Magnesium Sulfate

Answer: MgSO4

3) Aluminum Phosphate

Answer: AlPO4

4) Ammonium Hydroxide

Answer: NH4OH

5) Iron (II) Sulfate

Answer: FeSO4

6) Calcium Phosphate

Answer: Ca3(PO4)2

For assistance,
look back at the
rules for naming
Ionic Compounds

Summarize:
(you can always write you own)
• Explain the difference between a Ionic Compound and a Covalent
Compound:
• What numbers do the following prefixes represent: tetra-, tri-, penta- ,
hexa• Write down the polyatomic ions you need to memorize, arrange them in
order according to their charge:
• Explain how we name polyatomic compounds:
• Explain how we write formulas for polyatomic compounds:
• What do we do if more than one polyatomic ion is present in a
compound?


Slide 6

UNIT: Nomenclature
TOPIC: Covalent and Polyatomic Compounds
Objectives: Lesson 2 of 3
• You will learn what a Covalent Compound is
• You will learn how to write the formulas and names for Covalent
Compounds
• You will learn and hopefully memorize the most common
polyatomic ions
• You will also learn how to write formulas and names of polyatomic
compounds

Quickwrite
In 1-2 sentences answer one of the questions below:
• Consider the Compound CO2, how is this compound
different from NaCl (hint: look at their location on the periodic
table)???

• Why do you think we use prefixes such as “tri-” on
words like triceratops, tricycle or tripod?

Covalent Compounds

•• Earlier
learned
about
Notice,we
that
the electrons
Ionic Compounds which
are not
transferred,
form
between
cationsBUT,
instead,metals)
they are
shared
(usually
and
anions
(usually
a nonbetween
the two
atoms
metals)
•• Covalent
As a result,
Covalent
Compounds
Compounds
DOorNOT
have
form
when two
more
non-metal
elements
charges like
Ionic
share
electrons
Compounds
• Recall that Hydrogen is
• classified
Therefore,
use a
aswe
a non-metal
on
the periodic
table
completely
different
• The
simplest
covalent
naming
system
when
compound is Hydrogen
writing
gas
or H2their chemical

formulas and names

H2 - Covalent Compound

Cations+

(usually metals)

-

-

+

What is a Covalent Compound?
• A compound formed between two non-metals
that involves the sharing of electrons
• Example: CO, Carbon Monoxide

Covalent Compounds:
• When naming covalent compounds there are certain steps you must follow
• These steps will help you throughout this unit and the rest of the course:

1. The first element in the formula is named first,
and the full element name is used
2. The 2nd element is named as though it were an anion (add –ide)
3. Prefixes (mono- 1, di- 2, tri- 3) are used to denote
the numbers of atoms

4. The prefix mono- is never used for naming the first element

Prefixes
Prefix

Example

mono- (one)

CO

- carbon monoxide

di- (two)

CO2 - carbon dioxide

tri- (three)

N2O3 - dinitrogen trioxide

tetra- (four)

CCl4 - carbon tetrachloride

penta- (five)

N2O5 - dinitrogen pentoxide

hexa- (six)

UF6 - uranium hexafluoride

Covalent Compounds:
• Write the name for the covalent compound CO Carbon Monoxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Carbon” for Carbon Monoxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in CO is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: Since there is 1 oxygen atom we would use the prefix mono- for Monoxide
4. The prefix mono- is never used for naming the first element
For Example: CO is called Carbon Monoxide NOT Monocarbon Monoxide

Covalent Compounds:
• Write the name for the covalent compound SO3
Sulfur Trioxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Sulfur” for Sulfur Trioxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in SO3 is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: Since there are 3 oxygen atoms we would use the prefix tri- for Trioxide
4. The prefix mono- is never used for naming the first element
For Example: SO3 is called Sulfur Trioxide NOT Monosulfur Trioxide

Covalent Compounds:
• Write the name for the covalent compound
N2O5 - Dinitrogen Pentaoxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Nitrogen” for Dinitrogen Pentaoxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in N2O5 is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: there are 5 oxygen atoms so we would use the prefix penta- for Pentaoxide
4. The prefix mono- is never used for naming the first element
For Example: Since their are 2 nitrogen atoms, we use the prefix di- for Dinitrogen

What are the Steps for
Covalent Compounds?
1. The first element in the formula is named first, and the full
element name is used
2. The 2nd element is named as though it were an anion
3. Prefixes are used to denote the numbers of atomsmono- 1, di- 2, tri- 3, tetra- 4, penta- 5, hexa- 6
4. The prefix mono- is never used for naming the first element

Practice:

Write the names for the following compounds below:
1) SF6

Answer: Sulfur Hexafluoride

2) PCl5

Answer: Phosphorous Pentachloride

3) N2O4

Answer: Dinitrogen Tetraoxide

4) CCl4

Answer: Carbon Tetrachloride

5) CO2

Answer: Carbon Dioxide

6) NO2

Answer: Nitrogen Dioxide

Practice:

Write the formulas for the following compounds below:
1) Dinitrogen Dioxide

Answer: N2O2

2) Sulfur Trioxide

Answer: SO3

3) Diphosphorous Pentaoxide Answer: P2O5
4) Nitrogen Monoxide

Answer: NO

5) Carbon Tetrafluoride

Answer: CF4

6) Silcon Dioxide

Answer: SiO2

Polyatomic Ions

• Polyatomic Ions are a group of two or more atoms
that have a particular charge to them
+1
• An example would include the ammonium ion

[

+
]

• It is composed of
atom and
atoms which give it a +1 charge
• These ions are assigned special names that you
must memorize!

Polyatomic Ions

• Common Polyatomic Ions:
Name

Formula

Name

Formula

nitrate

NO3-1

chromate

CrO4-2

chlorate

ClO3-1

phospite

PO3-3

sulfate

SO4-2

phosphate

PO4-3

carbonate

CO3-2

acetate

C2H3O2-1

hydroxide

OH -1

cyanide

CN-1

ammonium

NH4+1

sulfite

SO3-2

What are Polyatomic Ions?
• A group of two or more atoms that have a
particular charge to them
• No naming rules exist, you must memorize
their names and charge
• Polyatomic Ions
nitrate
NO
chromate
CrO
ClO
phospite
PO
you must memorize: chlorate
sulfate
SO
phosphate PO
Name

Formula

Name

Formula

carbonate

-1
3
-1
3
-2
4
CO3-2

acetate

C2H3O2-1

hydroxide

OH -1

cyanide

CN-1

sulfite

SO3-2

ammonium NH4+1

-2
4
-3
3
-3
4

Practice:

Write the formula and charge for each polyatomic ion
below:
1) hydroxide

Answer: OH-

2) nitrate

Answer: NO3-

3) phosphate

Answer: PO4-3

4) sulfate

Answer: SO4-2

Ionic Compounds with Polyatomic Ions
• Naming ionic compounds that contain polyatomic
ions is very similar to naming ionic compounds
• For example, the compound NaOH contains the
cation, Sodium (Na+1) and the polyatomic ion
hydroxide (OH-1)
• Remember, when Ionic compounds come together,
their charges must always be neutral or ZERO
• Just like ionic compounds, we write the cation first
and the anion second; giving us the compound
Sodium Hydroxide--NaOH

Ionic Compounds with Polyatomic Ions
• Let us look at the compound ammonium nitrate
NH4NO3 (a very explosive chemical)
• Ammonium Nitrate is made up of 2 polyatomic
ions Ammonium (NH4+ ) & Nitrate (NO3-)
• When two polyatomic ions come together, a
neutral compound NH4NO3 forms between them
• Notice, the cation is named first, and anion
second

Ionic Compounds with Polyatomic Ions
• Consider Silver (I) Nitrate: AgNO3
• The Silver (Ag+1) cation comes first, and the polyatomic
anion Nitrate (NO3-1) comes second
• Just like in ionic compounds, the charges need to be
neutral
• The Silver cation Ag+ with a plus one charge is balanced
by the negatively charged polyatomic ion NO3-1 with a
negative one charge
• It is important to realize that because Silver (Ag) is a
transition metal it takes on multiple charges, therefore we
still use roman numerals to illustrate charge
• Therefore we write: Silver (I) Nitrate

Ionic Compounds with Polyatomic Ions
• Consider one more compound: Mg(OH)2
• The Mg+2 cation comes first, and the negative polyatomic
OH- anion comes second
• Just like in ionic compounds, the charges need to be
neutral
• Mg+2 needs be balanced by 2 negatively charged
polyatomic ions OH( )2 when more than one polyatomic
• In the case of Mg(OH)
ion exists, we put PARENTHESIS around them
• By putting parenthesis around (OH)2 and a subscript of 2,
this tells us we have 2 oxygen atoms and 2 hydrogen
atoms

What are Ionic Compounds
with Polyatomic Ions?
• Neutrally charged Compounds that contain a
polyatomic ion
• When more than one polyatomic ion exists in a
compound we put parenthesis around them
• Ex: Mg(OH)2 & AgNO3

Practice:

Write the names for the following compounds below:
1) NaOH

Answer: Sodium Hydroxide

2) Ba(OH)2

Answer: Barium Hydroxide

3) NH4Cl

Answer: Ammonium Chloride

4) AgNO3

Answer: Silver (I) Nitrate

5) CaCO3

Answer: Calcium Carbonate

6) Mg(NO3)2

Answer: Magnesium Nitrate

For assistance,
look back at the
rules for naming
Ionic Compounds

Practice:

Write the formulas for the following compounds below:
1) Calcium Hydroxide

Answer: Ca(OH)2

2) Magnesium Sulfate

Answer: MgSO4

3) Aluminum Phosphate

Answer: AlPO4

4) Ammonium Hydroxide

Answer: NH4OH

5) Iron (II) Sulfate

Answer: FeSO4

6) Calcium Phosphate

Answer: Ca3(PO4)2

For assistance,
look back at the
rules for naming
Ionic Compounds

Summarize:
(you can always write you own)
• Explain the difference between a Ionic Compound and a Covalent
Compound:
• What numbers do the following prefixes represent: tetra-, tri-, penta- ,
hexa• Write down the polyatomic ions you need to memorize, arrange them in
order according to their charge:
• Explain how we name polyatomic compounds:
• Explain how we write formulas for polyatomic compounds:
• What do we do if more than one polyatomic ion is present in a
compound?


Slide 7

UNIT: Nomenclature
TOPIC: Covalent and Polyatomic Compounds
Objectives: Lesson 2 of 3
• You will learn what a Covalent Compound is
• You will learn how to write the formulas and names for Covalent
Compounds
• You will learn and hopefully memorize the most common
polyatomic ions
• You will also learn how to write formulas and names of polyatomic
compounds

Quickwrite
In 1-2 sentences answer one of the questions below:
• Consider the Compound CO2, how is this compound
different from NaCl (hint: look at their location on the periodic
table)???

• Why do you think we use prefixes such as “tri-” on
words like triceratops, tricycle or tripod?

Covalent Compounds

•• Earlier
learned
about
Notice,we
that
the electrons
Ionic Compounds which
are not
transferred,
form
between
cationsBUT,
instead,metals)
they are
shared
(usually
and
anions
(usually
a nonbetween
the two
atoms
metals)
•• Covalent
As a result,
Covalent
Compounds
Compounds
DOorNOT
have
form
when two
more
non-metal
elements
charges like
Ionic
share
electrons
Compounds
• Recall that Hydrogen is
• classified
Therefore,
use a
aswe
a non-metal
on
the periodic
table
completely
different
• The
simplest
covalent
naming
system
when
compound is Hydrogen
writing
gas
or H2their chemical

formulas and names

H2 - Covalent Compound

Cations+

(usually metals)

-

-

+

What is a Covalent Compound?
• A compound formed between two non-metals
that involves the sharing of electrons
• Example: CO, Carbon Monoxide

Covalent Compounds:
• When naming covalent compounds there are certain steps you must follow
• These steps will help you throughout this unit and the rest of the course:

1. The first element in the formula is named first,
and the full element name is used
2. The 2nd element is named as though it were an anion (add –ide)
3. Prefixes (mono- 1, di- 2, tri- 3) are used to denote
the numbers of atoms

4. The prefix mono- is never used for naming the first element

Prefixes
Prefix

Example

mono- (one)

CO

- carbon monoxide

di- (two)

CO2 - carbon dioxide

tri- (three)

N2O3 - dinitrogen trioxide

tetra- (four)

CCl4 - carbon tetrachloride

penta- (five)

N2O5 - dinitrogen pentoxide

hexa- (six)

UF6 - uranium hexafluoride

Covalent Compounds:
• Write the name for the covalent compound CO Carbon Monoxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Carbon” for Carbon Monoxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in CO is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: Since there is 1 oxygen atom we would use the prefix mono- for Monoxide
4. The prefix mono- is never used for naming the first element
For Example: CO is called Carbon Monoxide NOT Monocarbon Monoxide

Covalent Compounds:
• Write the name for the covalent compound SO3
Sulfur Trioxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Sulfur” for Sulfur Trioxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in SO3 is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: Since there are 3 oxygen atoms we would use the prefix tri- for Trioxide
4. The prefix mono- is never used for naming the first element
For Example: SO3 is called Sulfur Trioxide NOT Monosulfur Trioxide

Covalent Compounds:
• Write the name for the covalent compound
N2O5 - Dinitrogen Pentaoxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Nitrogen” for Dinitrogen Pentaoxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in N2O5 is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: there are 5 oxygen atoms so we would use the prefix penta- for Pentaoxide
4. The prefix mono- is never used for naming the first element
For Example: Since their are 2 nitrogen atoms, we use the prefix di- for Dinitrogen

What are the Steps for
Covalent Compounds?
1. The first element in the formula is named first, and the full
element name is used
2. The 2nd element is named as though it were an anion
3. Prefixes are used to denote the numbers of atomsmono- 1, di- 2, tri- 3, tetra- 4, penta- 5, hexa- 6
4. The prefix mono- is never used for naming the first element

Practice:

Write the names for the following compounds below:
1) SF6

Answer: Sulfur Hexafluoride

2) PCl5

Answer: Phosphorous Pentachloride

3) N2O4

Answer: Dinitrogen Tetraoxide

4) CCl4

Answer: Carbon Tetrachloride

5) CO2

Answer: Carbon Dioxide

6) NO2

Answer: Nitrogen Dioxide

Practice:

Write the formulas for the following compounds below:
1) Dinitrogen Dioxide

Answer: N2O2

2) Sulfur Trioxide

Answer: SO3

3) Diphosphorous Pentaoxide Answer: P2O5
4) Nitrogen Monoxide

Answer: NO

5) Carbon Tetrafluoride

Answer: CF4

6) Silcon Dioxide

Answer: SiO2

Polyatomic Ions

• Polyatomic Ions are a group of two or more atoms
that have a particular charge to them
+1
• An example would include the ammonium ion

[

+
]

• It is composed of
atom and
atoms which give it a +1 charge
• These ions are assigned special names that you
must memorize!

Polyatomic Ions

• Common Polyatomic Ions:
Name

Formula

Name

Formula

nitrate

NO3-1

chromate

CrO4-2

chlorate

ClO3-1

phospite

PO3-3

sulfate

SO4-2

phosphate

PO4-3

carbonate

CO3-2

acetate

C2H3O2-1

hydroxide

OH -1

cyanide

CN-1

ammonium

NH4+1

sulfite

SO3-2

What are Polyatomic Ions?
• A group of two or more atoms that have a
particular charge to them
• No naming rules exist, you must memorize
their names and charge
• Polyatomic Ions
nitrate
NO
chromate
CrO
ClO
phospite
PO
you must memorize: chlorate
sulfate
SO
phosphate PO
Name

Formula

Name

Formula

carbonate

-1
3
-1
3
-2
4
CO3-2

acetate

C2H3O2-1

hydroxide

OH -1

cyanide

CN-1

sulfite

SO3-2

ammonium NH4+1

-2
4
-3
3
-3
4

Practice:

Write the formula and charge for each polyatomic ion
below:
1) hydroxide

Answer: OH-

2) nitrate

Answer: NO3-

3) phosphate

Answer: PO4-3

4) sulfate

Answer: SO4-2

Ionic Compounds with Polyatomic Ions
• Naming ionic compounds that contain polyatomic
ions is very similar to naming ionic compounds
• For example, the compound NaOH contains the
cation, Sodium (Na+1) and the polyatomic ion
hydroxide (OH-1)
• Remember, when Ionic compounds come together,
their charges must always be neutral or ZERO
• Just like ionic compounds, we write the cation first
and the anion second; giving us the compound
Sodium Hydroxide--NaOH

Ionic Compounds with Polyatomic Ions
• Let us look at the compound ammonium nitrate
NH4NO3 (a very explosive chemical)
• Ammonium Nitrate is made up of 2 polyatomic
ions Ammonium (NH4+ ) & Nitrate (NO3-)
• When two polyatomic ions come together, a
neutral compound NH4NO3 forms between them
• Notice, the cation is named first, and anion
second

Ionic Compounds with Polyatomic Ions
• Consider Silver (I) Nitrate: AgNO3
• The Silver (Ag+1) cation comes first, and the polyatomic
anion Nitrate (NO3-1) comes second
• Just like in ionic compounds, the charges need to be
neutral
• The Silver cation Ag+ with a plus one charge is balanced
by the negatively charged polyatomic ion NO3-1 with a
negative one charge
• It is important to realize that because Silver (Ag) is a
transition metal it takes on multiple charges, therefore we
still use roman numerals to illustrate charge
• Therefore we write: Silver (I) Nitrate

Ionic Compounds with Polyatomic Ions
• Consider one more compound: Mg(OH)2
• The Mg+2 cation comes first, and the negative polyatomic
OH- anion comes second
• Just like in ionic compounds, the charges need to be
neutral
• Mg+2 needs be balanced by 2 negatively charged
polyatomic ions OH( )2 when more than one polyatomic
• In the case of Mg(OH)
ion exists, we put PARENTHESIS around them
• By putting parenthesis around (OH)2 and a subscript of 2,
this tells us we have 2 oxygen atoms and 2 hydrogen
atoms

What are Ionic Compounds
with Polyatomic Ions?
• Neutrally charged Compounds that contain a
polyatomic ion
• When more than one polyatomic ion exists in a
compound we put parenthesis around them
• Ex: Mg(OH)2 & AgNO3

Practice:

Write the names for the following compounds below:
1) NaOH

Answer: Sodium Hydroxide

2) Ba(OH)2

Answer: Barium Hydroxide

3) NH4Cl

Answer: Ammonium Chloride

4) AgNO3

Answer: Silver (I) Nitrate

5) CaCO3

Answer: Calcium Carbonate

6) Mg(NO3)2

Answer: Magnesium Nitrate

For assistance,
look back at the
rules for naming
Ionic Compounds

Practice:

Write the formulas for the following compounds below:
1) Calcium Hydroxide

Answer: Ca(OH)2

2) Magnesium Sulfate

Answer: MgSO4

3) Aluminum Phosphate

Answer: AlPO4

4) Ammonium Hydroxide

Answer: NH4OH

5) Iron (II) Sulfate

Answer: FeSO4

6) Calcium Phosphate

Answer: Ca3(PO4)2

For assistance,
look back at the
rules for naming
Ionic Compounds

Summarize:
(you can always write you own)
• Explain the difference between a Ionic Compound and a Covalent
Compound:
• What numbers do the following prefixes represent: tetra-, tri-, penta- ,
hexa• Write down the polyatomic ions you need to memorize, arrange them in
order according to their charge:
• Explain how we name polyatomic compounds:
• Explain how we write formulas for polyatomic compounds:
• What do we do if more than one polyatomic ion is present in a
compound?


Slide 8

UNIT: Nomenclature
TOPIC: Covalent and Polyatomic Compounds
Objectives: Lesson 2 of 3
• You will learn what a Covalent Compound is
• You will learn how to write the formulas and names for Covalent
Compounds
• You will learn and hopefully memorize the most common
polyatomic ions
• You will also learn how to write formulas and names of polyatomic
compounds

Quickwrite
In 1-2 sentences answer one of the questions below:
• Consider the Compound CO2, how is this compound
different from NaCl (hint: look at their location on the periodic
table)???

• Why do you think we use prefixes such as “tri-” on
words like triceratops, tricycle or tripod?

Covalent Compounds

•• Earlier
learned
about
Notice,we
that
the electrons
Ionic Compounds which
are not
transferred,
form
between
cationsBUT,
instead,metals)
they are
shared
(usually
and
anions
(usually
a nonbetween
the two
atoms
metals)
•• Covalent
As a result,
Covalent
Compounds
Compounds
DOorNOT
have
form
when two
more
non-metal
elements
charges like
Ionic
share
electrons
Compounds
• Recall that Hydrogen is
• classified
Therefore,
use a
aswe
a non-metal
on
the periodic
table
completely
different
• The
simplest
covalent
naming
system
when
compound is Hydrogen
writing
gas
or H2their chemical

formulas and names

H2 - Covalent Compound

Cations+

(usually metals)

-

-

+

What is a Covalent Compound?
• A compound formed between two non-metals
that involves the sharing of electrons
• Example: CO, Carbon Monoxide

Covalent Compounds:
• When naming covalent compounds there are certain steps you must follow
• These steps will help you throughout this unit and the rest of the course:

1. The first element in the formula is named first,
and the full element name is used
2. The 2nd element is named as though it were an anion (add –ide)
3. Prefixes (mono- 1, di- 2, tri- 3) are used to denote
the numbers of atoms

4. The prefix mono- is never used for naming the first element

Prefixes
Prefix

Example

mono- (one)

CO

- carbon monoxide

di- (two)

CO2 - carbon dioxide

tri- (three)

N2O3 - dinitrogen trioxide

tetra- (four)

CCl4 - carbon tetrachloride

penta- (five)

N2O5 - dinitrogen pentoxide

hexa- (six)

UF6 - uranium hexafluoride

Covalent Compounds:
• Write the name for the covalent compound CO Carbon Monoxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Carbon” for Carbon Monoxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in CO is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: Since there is 1 oxygen atom we would use the prefix mono- for Monoxide
4. The prefix mono- is never used for naming the first element
For Example: CO is called Carbon Monoxide NOT Monocarbon Monoxide

Covalent Compounds:
• Write the name for the covalent compound SO3
Sulfur Trioxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Sulfur” for Sulfur Trioxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in SO3 is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: Since there are 3 oxygen atoms we would use the prefix tri- for Trioxide
4. The prefix mono- is never used for naming the first element
For Example: SO3 is called Sulfur Trioxide NOT Monosulfur Trioxide

Covalent Compounds:
• Write the name for the covalent compound
N2O5 - Dinitrogen Pentaoxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Nitrogen” for Dinitrogen Pentaoxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in N2O5 is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: there are 5 oxygen atoms so we would use the prefix penta- for Pentaoxide
4. The prefix mono- is never used for naming the first element
For Example: Since their are 2 nitrogen atoms, we use the prefix di- for Dinitrogen

What are the Steps for
Covalent Compounds?
1. The first element in the formula is named first, and the full
element name is used
2. The 2nd element is named as though it were an anion
3. Prefixes are used to denote the numbers of atomsmono- 1, di- 2, tri- 3, tetra- 4, penta- 5, hexa- 6
4. The prefix mono- is never used for naming the first element

Practice:

Write the names for the following compounds below:
1) SF6

Answer: Sulfur Hexafluoride

2) PCl5

Answer: Phosphorous Pentachloride

3) N2O4

Answer: Dinitrogen Tetraoxide

4) CCl4

Answer: Carbon Tetrachloride

5) CO2

Answer: Carbon Dioxide

6) NO2

Answer: Nitrogen Dioxide

Practice:

Write the formulas for the following compounds below:
1) Dinitrogen Dioxide

Answer: N2O2

2) Sulfur Trioxide

Answer: SO3

3) Diphosphorous Pentaoxide Answer: P2O5
4) Nitrogen Monoxide

Answer: NO

5) Carbon Tetrafluoride

Answer: CF4

6) Silcon Dioxide

Answer: SiO2

Polyatomic Ions

• Polyatomic Ions are a group of two or more atoms
that have a particular charge to them
+1
• An example would include the ammonium ion

[

+
]

• It is composed of
atom and
atoms which give it a +1 charge
• These ions are assigned special names that you
must memorize!

Polyatomic Ions

• Common Polyatomic Ions:
Name

Formula

Name

Formula

nitrate

NO3-1

chromate

CrO4-2

chlorate

ClO3-1

phospite

PO3-3

sulfate

SO4-2

phosphate

PO4-3

carbonate

CO3-2

acetate

C2H3O2-1

hydroxide

OH -1

cyanide

CN-1

ammonium

NH4+1

sulfite

SO3-2

What are Polyatomic Ions?
• A group of two or more atoms that have a
particular charge to them
• No naming rules exist, you must memorize
their names and charge
• Polyatomic Ions
nitrate
NO
chromate
CrO
ClO
phospite
PO
you must memorize: chlorate
sulfate
SO
phosphate PO
Name

Formula

Name

Formula

carbonate

-1
3
-1
3
-2
4
CO3-2

acetate

C2H3O2-1

hydroxide

OH -1

cyanide

CN-1

sulfite

SO3-2

ammonium NH4+1

-2
4
-3
3
-3
4

Practice:

Write the formula and charge for each polyatomic ion
below:
1) hydroxide

Answer: OH-

2) nitrate

Answer: NO3-

3) phosphate

Answer: PO4-3

4) sulfate

Answer: SO4-2

Ionic Compounds with Polyatomic Ions
• Naming ionic compounds that contain polyatomic
ions is very similar to naming ionic compounds
• For example, the compound NaOH contains the
cation, Sodium (Na+1) and the polyatomic ion
hydroxide (OH-1)
• Remember, when Ionic compounds come together,
their charges must always be neutral or ZERO
• Just like ionic compounds, we write the cation first
and the anion second; giving us the compound
Sodium Hydroxide--NaOH

Ionic Compounds with Polyatomic Ions
• Let us look at the compound ammonium nitrate
NH4NO3 (a very explosive chemical)
• Ammonium Nitrate is made up of 2 polyatomic
ions Ammonium (NH4+ ) & Nitrate (NO3-)
• When two polyatomic ions come together, a
neutral compound NH4NO3 forms between them
• Notice, the cation is named first, and anion
second

Ionic Compounds with Polyatomic Ions
• Consider Silver (I) Nitrate: AgNO3
• The Silver (Ag+1) cation comes first, and the polyatomic
anion Nitrate (NO3-1) comes second
• Just like in ionic compounds, the charges need to be
neutral
• The Silver cation Ag+ with a plus one charge is balanced
by the negatively charged polyatomic ion NO3-1 with a
negative one charge
• It is important to realize that because Silver (Ag) is a
transition metal it takes on multiple charges, therefore we
still use roman numerals to illustrate charge
• Therefore we write: Silver (I) Nitrate

Ionic Compounds with Polyatomic Ions
• Consider one more compound: Mg(OH)2
• The Mg+2 cation comes first, and the negative polyatomic
OH- anion comes second
• Just like in ionic compounds, the charges need to be
neutral
• Mg+2 needs be balanced by 2 negatively charged
polyatomic ions OH( )2 when more than one polyatomic
• In the case of Mg(OH)
ion exists, we put PARENTHESIS around them
• By putting parenthesis around (OH)2 and a subscript of 2,
this tells us we have 2 oxygen atoms and 2 hydrogen
atoms

What are Ionic Compounds
with Polyatomic Ions?
• Neutrally charged Compounds that contain a
polyatomic ion
• When more than one polyatomic ion exists in a
compound we put parenthesis around them
• Ex: Mg(OH)2 & AgNO3

Practice:

Write the names for the following compounds below:
1) NaOH

Answer: Sodium Hydroxide

2) Ba(OH)2

Answer: Barium Hydroxide

3) NH4Cl

Answer: Ammonium Chloride

4) AgNO3

Answer: Silver (I) Nitrate

5) CaCO3

Answer: Calcium Carbonate

6) Mg(NO3)2

Answer: Magnesium Nitrate

For assistance,
look back at the
rules for naming
Ionic Compounds

Practice:

Write the formulas for the following compounds below:
1) Calcium Hydroxide

Answer: Ca(OH)2

2) Magnesium Sulfate

Answer: MgSO4

3) Aluminum Phosphate

Answer: AlPO4

4) Ammonium Hydroxide

Answer: NH4OH

5) Iron (II) Sulfate

Answer: FeSO4

6) Calcium Phosphate

Answer: Ca3(PO4)2

For assistance,
look back at the
rules for naming
Ionic Compounds

Summarize:
(you can always write you own)
• Explain the difference between a Ionic Compound and a Covalent
Compound:
• What numbers do the following prefixes represent: tetra-, tri-, penta- ,
hexa• Write down the polyatomic ions you need to memorize, arrange them in
order according to their charge:
• Explain how we name polyatomic compounds:
• Explain how we write formulas for polyatomic compounds:
• What do we do if more than one polyatomic ion is present in a
compound?


Slide 9

UNIT: Nomenclature
TOPIC: Covalent and Polyatomic Compounds
Objectives: Lesson 2 of 3
• You will learn what a Covalent Compound is
• You will learn how to write the formulas and names for Covalent
Compounds
• You will learn and hopefully memorize the most common
polyatomic ions
• You will also learn how to write formulas and names of polyatomic
compounds

Quickwrite
In 1-2 sentences answer one of the questions below:
• Consider the Compound CO2, how is this compound
different from NaCl (hint: look at their location on the periodic
table)???

• Why do you think we use prefixes such as “tri-” on
words like triceratops, tricycle or tripod?

Covalent Compounds

•• Earlier
learned
about
Notice,we
that
the electrons
Ionic Compounds which
are not
transferred,
form
between
cationsBUT,
instead,metals)
they are
shared
(usually
and
anions
(usually
a nonbetween
the two
atoms
metals)
•• Covalent
As a result,
Covalent
Compounds
Compounds
DOorNOT
have
form
when two
more
non-metal
elements
charges like
Ionic
share
electrons
Compounds
• Recall that Hydrogen is
• classified
Therefore,
use a
aswe
a non-metal
on
the periodic
table
completely
different
• The
simplest
covalent
naming
system
when
compound is Hydrogen
writing
gas
or H2their chemical

formulas and names

H2 - Covalent Compound

Cations+

(usually metals)

-

-

+

What is a Covalent Compound?
• A compound formed between two non-metals
that involves the sharing of electrons
• Example: CO, Carbon Monoxide

Covalent Compounds:
• When naming covalent compounds there are certain steps you must follow
• These steps will help you throughout this unit and the rest of the course:

1. The first element in the formula is named first,
and the full element name is used
2. The 2nd element is named as though it were an anion (add –ide)
3. Prefixes (mono- 1, di- 2, tri- 3) are used to denote
the numbers of atoms

4. The prefix mono- is never used for naming the first element

Prefixes
Prefix

Example

mono- (one)

CO

- carbon monoxide

di- (two)

CO2 - carbon dioxide

tri- (three)

N2O3 - dinitrogen trioxide

tetra- (four)

CCl4 - carbon tetrachloride

penta- (five)

N2O5 - dinitrogen pentoxide

hexa- (six)

UF6 - uranium hexafluoride

Covalent Compounds:
• Write the name for the covalent compound CO Carbon Monoxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Carbon” for Carbon Monoxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in CO is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: Since there is 1 oxygen atom we would use the prefix mono- for Monoxide
4. The prefix mono- is never used for naming the first element
For Example: CO is called Carbon Monoxide NOT Monocarbon Monoxide

Covalent Compounds:
• Write the name for the covalent compound SO3
Sulfur Trioxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Sulfur” for Sulfur Trioxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in SO3 is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: Since there are 3 oxygen atoms we would use the prefix tri- for Trioxide
4. The prefix mono- is never used for naming the first element
For Example: SO3 is called Sulfur Trioxide NOT Monosulfur Trioxide

Covalent Compounds:
• Write the name for the covalent compound
N2O5 - Dinitrogen Pentaoxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Nitrogen” for Dinitrogen Pentaoxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in N2O5 is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: there are 5 oxygen atoms so we would use the prefix penta- for Pentaoxide
4. The prefix mono- is never used for naming the first element
For Example: Since their are 2 nitrogen atoms, we use the prefix di- for Dinitrogen

What are the Steps for
Covalent Compounds?
1. The first element in the formula is named first, and the full
element name is used
2. The 2nd element is named as though it were an anion
3. Prefixes are used to denote the numbers of atomsmono- 1, di- 2, tri- 3, tetra- 4, penta- 5, hexa- 6
4. The prefix mono- is never used for naming the first element

Practice:

Write the names for the following compounds below:
1) SF6

Answer: Sulfur Hexafluoride

2) PCl5

Answer: Phosphorous Pentachloride

3) N2O4

Answer: Dinitrogen Tetraoxide

4) CCl4

Answer: Carbon Tetrachloride

5) CO2

Answer: Carbon Dioxide

6) NO2

Answer: Nitrogen Dioxide

Practice:

Write the formulas for the following compounds below:
1) Dinitrogen Dioxide

Answer: N2O2

2) Sulfur Trioxide

Answer: SO3

3) Diphosphorous Pentaoxide Answer: P2O5
4) Nitrogen Monoxide

Answer: NO

5) Carbon Tetrafluoride

Answer: CF4

6) Silcon Dioxide

Answer: SiO2

Polyatomic Ions

• Polyatomic Ions are a group of two or more atoms
that have a particular charge to them
+1
• An example would include the ammonium ion

[

+
]

• It is composed of
atom and
atoms which give it a +1 charge
• These ions are assigned special names that you
must memorize!

Polyatomic Ions

• Common Polyatomic Ions:
Name

Formula

Name

Formula

nitrate

NO3-1

chromate

CrO4-2

chlorate

ClO3-1

phospite

PO3-3

sulfate

SO4-2

phosphate

PO4-3

carbonate

CO3-2

acetate

C2H3O2-1

hydroxide

OH -1

cyanide

CN-1

ammonium

NH4+1

sulfite

SO3-2

What are Polyatomic Ions?
• A group of two or more atoms that have a
particular charge to them
• No naming rules exist, you must memorize
their names and charge
• Polyatomic Ions
nitrate
NO
chromate
CrO
ClO
phospite
PO
you must memorize: chlorate
sulfate
SO
phosphate PO
Name

Formula

Name

Formula

carbonate

-1
3
-1
3
-2
4
CO3-2

acetate

C2H3O2-1

hydroxide

OH -1

cyanide

CN-1

sulfite

SO3-2

ammonium NH4+1

-2
4
-3
3
-3
4

Practice:

Write the formula and charge for each polyatomic ion
below:
1) hydroxide

Answer: OH-

2) nitrate

Answer: NO3-

3) phosphate

Answer: PO4-3

4) sulfate

Answer: SO4-2

Ionic Compounds with Polyatomic Ions
• Naming ionic compounds that contain polyatomic
ions is very similar to naming ionic compounds
• For example, the compound NaOH contains the
cation, Sodium (Na+1) and the polyatomic ion
hydroxide (OH-1)
• Remember, when Ionic compounds come together,
their charges must always be neutral or ZERO
• Just like ionic compounds, we write the cation first
and the anion second; giving us the compound
Sodium Hydroxide--NaOH

Ionic Compounds with Polyatomic Ions
• Let us look at the compound ammonium nitrate
NH4NO3 (a very explosive chemical)
• Ammonium Nitrate is made up of 2 polyatomic
ions Ammonium (NH4+ ) & Nitrate (NO3-)
• When two polyatomic ions come together, a
neutral compound NH4NO3 forms between them
• Notice, the cation is named first, and anion
second

Ionic Compounds with Polyatomic Ions
• Consider Silver (I) Nitrate: AgNO3
• The Silver (Ag+1) cation comes first, and the polyatomic
anion Nitrate (NO3-1) comes second
• Just like in ionic compounds, the charges need to be
neutral
• The Silver cation Ag+ with a plus one charge is balanced
by the negatively charged polyatomic ion NO3-1 with a
negative one charge
• It is important to realize that because Silver (Ag) is a
transition metal it takes on multiple charges, therefore we
still use roman numerals to illustrate charge
• Therefore we write: Silver (I) Nitrate

Ionic Compounds with Polyatomic Ions
• Consider one more compound: Mg(OH)2
• The Mg+2 cation comes first, and the negative polyatomic
OH- anion comes second
• Just like in ionic compounds, the charges need to be
neutral
• Mg+2 needs be balanced by 2 negatively charged
polyatomic ions OH( )2 when more than one polyatomic
• In the case of Mg(OH)
ion exists, we put PARENTHESIS around them
• By putting parenthesis around (OH)2 and a subscript of 2,
this tells us we have 2 oxygen atoms and 2 hydrogen
atoms

What are Ionic Compounds
with Polyatomic Ions?
• Neutrally charged Compounds that contain a
polyatomic ion
• When more than one polyatomic ion exists in a
compound we put parenthesis around them
• Ex: Mg(OH)2 & AgNO3

Practice:

Write the names for the following compounds below:
1) NaOH

Answer: Sodium Hydroxide

2) Ba(OH)2

Answer: Barium Hydroxide

3) NH4Cl

Answer: Ammonium Chloride

4) AgNO3

Answer: Silver (I) Nitrate

5) CaCO3

Answer: Calcium Carbonate

6) Mg(NO3)2

Answer: Magnesium Nitrate

For assistance,
look back at the
rules for naming
Ionic Compounds

Practice:

Write the formulas for the following compounds below:
1) Calcium Hydroxide

Answer: Ca(OH)2

2) Magnesium Sulfate

Answer: MgSO4

3) Aluminum Phosphate

Answer: AlPO4

4) Ammonium Hydroxide

Answer: NH4OH

5) Iron (II) Sulfate

Answer: FeSO4

6) Calcium Phosphate

Answer: Ca3(PO4)2

For assistance,
look back at the
rules for naming
Ionic Compounds

Summarize:
(you can always write you own)
• Explain the difference between a Ionic Compound and a Covalent
Compound:
• What numbers do the following prefixes represent: tetra-, tri-, penta- ,
hexa• Write down the polyatomic ions you need to memorize, arrange them in
order according to their charge:
• Explain how we name polyatomic compounds:
• Explain how we write formulas for polyatomic compounds:
• What do we do if more than one polyatomic ion is present in a
compound?


Slide 10

UNIT: Nomenclature
TOPIC: Covalent and Polyatomic Compounds
Objectives: Lesson 2 of 3
• You will learn what a Covalent Compound is
• You will learn how to write the formulas and names for Covalent
Compounds
• You will learn and hopefully memorize the most common
polyatomic ions
• You will also learn how to write formulas and names of polyatomic
compounds

Quickwrite
In 1-2 sentences answer one of the questions below:
• Consider the Compound CO2, how is this compound
different from NaCl (hint: look at their location on the periodic
table)???

• Why do you think we use prefixes such as “tri-” on
words like triceratops, tricycle or tripod?

Covalent Compounds

•• Earlier
learned
about
Notice,we
that
the electrons
Ionic Compounds which
are not
transferred,
form
between
cationsBUT,
instead,metals)
they are
shared
(usually
and
anions
(usually
a nonbetween
the two
atoms
metals)
•• Covalent
As a result,
Covalent
Compounds
Compounds
DOorNOT
have
form
when two
more
non-metal
elements
charges like
Ionic
share
electrons
Compounds
• Recall that Hydrogen is
• classified
Therefore,
use a
aswe
a non-metal
on
the periodic
table
completely
different
• The
simplest
covalent
naming
system
when
compound is Hydrogen
writing
gas
or H2their chemical

formulas and names

H2 - Covalent Compound

Cations+

(usually metals)

-

-

+

What is a Covalent Compound?
• A compound formed between two non-metals
that involves the sharing of electrons
• Example: CO, Carbon Monoxide

Covalent Compounds:
• When naming covalent compounds there are certain steps you must follow
• These steps will help you throughout this unit and the rest of the course:

1. The first element in the formula is named first,
and the full element name is used
2. The 2nd element is named as though it were an anion (add –ide)
3. Prefixes (mono- 1, di- 2, tri- 3) are used to denote
the numbers of atoms

4. The prefix mono- is never used for naming the first element

Prefixes
Prefix

Example

mono- (one)

CO

- carbon monoxide

di- (two)

CO2 - carbon dioxide

tri- (three)

N2O3 - dinitrogen trioxide

tetra- (four)

CCl4 - carbon tetrachloride

penta- (five)

N2O5 - dinitrogen pentoxide

hexa- (six)

UF6 - uranium hexafluoride

Covalent Compounds:
• Write the name for the covalent compound CO Carbon Monoxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Carbon” for Carbon Monoxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in CO is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: Since there is 1 oxygen atom we would use the prefix mono- for Monoxide
4. The prefix mono- is never used for naming the first element
For Example: CO is called Carbon Monoxide NOT Monocarbon Monoxide

Covalent Compounds:
• Write the name for the covalent compound SO3
Sulfur Trioxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Sulfur” for Sulfur Trioxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in SO3 is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: Since there are 3 oxygen atoms we would use the prefix tri- for Trioxide
4. The prefix mono- is never used for naming the first element
For Example: SO3 is called Sulfur Trioxide NOT Monosulfur Trioxide

Covalent Compounds:
• Write the name for the covalent compound
N2O5 - Dinitrogen Pentaoxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Nitrogen” for Dinitrogen Pentaoxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in N2O5 is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: there are 5 oxygen atoms so we would use the prefix penta- for Pentaoxide
4. The prefix mono- is never used for naming the first element
For Example: Since their are 2 nitrogen atoms, we use the prefix di- for Dinitrogen

What are the Steps for
Covalent Compounds?
1. The first element in the formula is named first, and the full
element name is used
2. The 2nd element is named as though it were an anion
3. Prefixes are used to denote the numbers of atomsmono- 1, di- 2, tri- 3, tetra- 4, penta- 5, hexa- 6
4. The prefix mono- is never used for naming the first element

Practice:

Write the names for the following compounds below:
1) SF6

Answer: Sulfur Hexafluoride

2) PCl5

Answer: Phosphorous Pentachloride

3) N2O4

Answer: Dinitrogen Tetraoxide

4) CCl4

Answer: Carbon Tetrachloride

5) CO2

Answer: Carbon Dioxide

6) NO2

Answer: Nitrogen Dioxide

Practice:

Write the formulas for the following compounds below:
1) Dinitrogen Dioxide

Answer: N2O2

2) Sulfur Trioxide

Answer: SO3

3) Diphosphorous Pentaoxide Answer: P2O5
4) Nitrogen Monoxide

Answer: NO

5) Carbon Tetrafluoride

Answer: CF4

6) Silcon Dioxide

Answer: SiO2

Polyatomic Ions

• Polyatomic Ions are a group of two or more atoms
that have a particular charge to them
+1
• An example would include the ammonium ion

[

+
]

• It is composed of
atom and
atoms which give it a +1 charge
• These ions are assigned special names that you
must memorize!

Polyatomic Ions

• Common Polyatomic Ions:
Name

Formula

Name

Formula

nitrate

NO3-1

chromate

CrO4-2

chlorate

ClO3-1

phospite

PO3-3

sulfate

SO4-2

phosphate

PO4-3

carbonate

CO3-2

acetate

C2H3O2-1

hydroxide

OH -1

cyanide

CN-1

ammonium

NH4+1

sulfite

SO3-2

What are Polyatomic Ions?
• A group of two or more atoms that have a
particular charge to them
• No naming rules exist, you must memorize
their names and charge
• Polyatomic Ions
nitrate
NO
chromate
CrO
ClO
phospite
PO
you must memorize: chlorate
sulfate
SO
phosphate PO
Name

Formula

Name

Formula

carbonate

-1
3
-1
3
-2
4
CO3-2

acetate

C2H3O2-1

hydroxide

OH -1

cyanide

CN-1

sulfite

SO3-2

ammonium NH4+1

-2
4
-3
3
-3
4

Practice:

Write the formula and charge for each polyatomic ion
below:
1) hydroxide

Answer: OH-

2) nitrate

Answer: NO3-

3) phosphate

Answer: PO4-3

4) sulfate

Answer: SO4-2

Ionic Compounds with Polyatomic Ions
• Naming ionic compounds that contain polyatomic
ions is very similar to naming ionic compounds
• For example, the compound NaOH contains the
cation, Sodium (Na+1) and the polyatomic ion
hydroxide (OH-1)
• Remember, when Ionic compounds come together,
their charges must always be neutral or ZERO
• Just like ionic compounds, we write the cation first
and the anion second; giving us the compound
Sodium Hydroxide--NaOH

Ionic Compounds with Polyatomic Ions
• Let us look at the compound ammonium nitrate
NH4NO3 (a very explosive chemical)
• Ammonium Nitrate is made up of 2 polyatomic
ions Ammonium (NH4+ ) & Nitrate (NO3-)
• When two polyatomic ions come together, a
neutral compound NH4NO3 forms between them
• Notice, the cation is named first, and anion
second

Ionic Compounds with Polyatomic Ions
• Consider Silver (I) Nitrate: AgNO3
• The Silver (Ag+1) cation comes first, and the polyatomic
anion Nitrate (NO3-1) comes second
• Just like in ionic compounds, the charges need to be
neutral
• The Silver cation Ag+ with a plus one charge is balanced
by the negatively charged polyatomic ion NO3-1 with a
negative one charge
• It is important to realize that because Silver (Ag) is a
transition metal it takes on multiple charges, therefore we
still use roman numerals to illustrate charge
• Therefore we write: Silver (I) Nitrate

Ionic Compounds with Polyatomic Ions
• Consider one more compound: Mg(OH)2
• The Mg+2 cation comes first, and the negative polyatomic
OH- anion comes second
• Just like in ionic compounds, the charges need to be
neutral
• Mg+2 needs be balanced by 2 negatively charged
polyatomic ions OH( )2 when more than one polyatomic
• In the case of Mg(OH)
ion exists, we put PARENTHESIS around them
• By putting parenthesis around (OH)2 and a subscript of 2,
this tells us we have 2 oxygen atoms and 2 hydrogen
atoms

What are Ionic Compounds
with Polyatomic Ions?
• Neutrally charged Compounds that contain a
polyatomic ion
• When more than one polyatomic ion exists in a
compound we put parenthesis around them
• Ex: Mg(OH)2 & AgNO3

Practice:

Write the names for the following compounds below:
1) NaOH

Answer: Sodium Hydroxide

2) Ba(OH)2

Answer: Barium Hydroxide

3) NH4Cl

Answer: Ammonium Chloride

4) AgNO3

Answer: Silver (I) Nitrate

5) CaCO3

Answer: Calcium Carbonate

6) Mg(NO3)2

Answer: Magnesium Nitrate

For assistance,
look back at the
rules for naming
Ionic Compounds

Practice:

Write the formulas for the following compounds below:
1) Calcium Hydroxide

Answer: Ca(OH)2

2) Magnesium Sulfate

Answer: MgSO4

3) Aluminum Phosphate

Answer: AlPO4

4) Ammonium Hydroxide

Answer: NH4OH

5) Iron (II) Sulfate

Answer: FeSO4

6) Calcium Phosphate

Answer: Ca3(PO4)2

For assistance,
look back at the
rules for naming
Ionic Compounds

Summarize:
(you can always write you own)
• Explain the difference between a Ionic Compound and a Covalent
Compound:
• What numbers do the following prefixes represent: tetra-, tri-, penta- ,
hexa• Write down the polyatomic ions you need to memorize, arrange them in
order according to their charge:
• Explain how we name polyatomic compounds:
• Explain how we write formulas for polyatomic compounds:
• What do we do if more than one polyatomic ion is present in a
compound?


Slide 11

UNIT: Nomenclature
TOPIC: Covalent and Polyatomic Compounds
Objectives: Lesson 2 of 3
• You will learn what a Covalent Compound is
• You will learn how to write the formulas and names for Covalent
Compounds
• You will learn and hopefully memorize the most common
polyatomic ions
• You will also learn how to write formulas and names of polyatomic
compounds

Quickwrite
In 1-2 sentences answer one of the questions below:
• Consider the Compound CO2, how is this compound
different from NaCl (hint: look at their location on the periodic
table)???

• Why do you think we use prefixes such as “tri-” on
words like triceratops, tricycle or tripod?

Covalent Compounds

•• Earlier
learned
about
Notice,we
that
the electrons
Ionic Compounds which
are not
transferred,
form
between
cationsBUT,
instead,metals)
they are
shared
(usually
and
anions
(usually
a nonbetween
the two
atoms
metals)
•• Covalent
As a result,
Covalent
Compounds
Compounds
DOorNOT
have
form
when two
more
non-metal
elements
charges like
Ionic
share
electrons
Compounds
• Recall that Hydrogen is
• classified
Therefore,
use a
aswe
a non-metal
on
the periodic
table
completely
different
• The
simplest
covalent
naming
system
when
compound is Hydrogen
writing
gas
or H2their chemical

formulas and names

H2 - Covalent Compound

Cations+

(usually metals)

-

-

+

What is a Covalent Compound?
• A compound formed between two non-metals
that involves the sharing of electrons
• Example: CO, Carbon Monoxide

Covalent Compounds:
• When naming covalent compounds there are certain steps you must follow
• These steps will help you throughout this unit and the rest of the course:

1. The first element in the formula is named first,
and the full element name is used
2. The 2nd element is named as though it were an anion (add –ide)
3. Prefixes (mono- 1, di- 2, tri- 3) are used to denote
the numbers of atoms

4. The prefix mono- is never used for naming the first element

Prefixes
Prefix

Example

mono- (one)

CO

- carbon monoxide

di- (two)

CO2 - carbon dioxide

tri- (three)

N2O3 - dinitrogen trioxide

tetra- (four)

CCl4 - carbon tetrachloride

penta- (five)

N2O5 - dinitrogen pentoxide

hexa- (six)

UF6 - uranium hexafluoride

Covalent Compounds:
• Write the name for the covalent compound CO Carbon Monoxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Carbon” for Carbon Monoxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in CO is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: Since there is 1 oxygen atom we would use the prefix mono- for Monoxide
4. The prefix mono- is never used for naming the first element
For Example: CO is called Carbon Monoxide NOT Monocarbon Monoxide

Covalent Compounds:
• Write the name for the covalent compound SO3
Sulfur Trioxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Sulfur” for Sulfur Trioxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in SO3 is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: Since there are 3 oxygen atoms we would use the prefix tri- for Trioxide
4. The prefix mono- is never used for naming the first element
For Example: SO3 is called Sulfur Trioxide NOT Monosulfur Trioxide

Covalent Compounds:
• Write the name for the covalent compound
N2O5 - Dinitrogen Pentaoxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Nitrogen” for Dinitrogen Pentaoxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in N2O5 is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: there are 5 oxygen atoms so we would use the prefix penta- for Pentaoxide
4. The prefix mono- is never used for naming the first element
For Example: Since their are 2 nitrogen atoms, we use the prefix di- for Dinitrogen

What are the Steps for
Covalent Compounds?
1. The first element in the formula is named first, and the full
element name is used
2. The 2nd element is named as though it were an anion
3. Prefixes are used to denote the numbers of atomsmono- 1, di- 2, tri- 3, tetra- 4, penta- 5, hexa- 6
4. The prefix mono- is never used for naming the first element

Practice:

Write the names for the following compounds below:
1) SF6

Answer: Sulfur Hexafluoride

2) PCl5

Answer: Phosphorous Pentachloride

3) N2O4

Answer: Dinitrogen Tetraoxide

4) CCl4

Answer: Carbon Tetrachloride

5) CO2

Answer: Carbon Dioxide

6) NO2

Answer: Nitrogen Dioxide

Practice:

Write the formulas for the following compounds below:
1) Dinitrogen Dioxide

Answer: N2O2

2) Sulfur Trioxide

Answer: SO3

3) Diphosphorous Pentaoxide Answer: P2O5
4) Nitrogen Monoxide

Answer: NO

5) Carbon Tetrafluoride

Answer: CF4

6) Silcon Dioxide

Answer: SiO2

Polyatomic Ions

• Polyatomic Ions are a group of two or more atoms
that have a particular charge to them
+1
• An example would include the ammonium ion

[

+
]

• It is composed of
atom and
atoms which give it a +1 charge
• These ions are assigned special names that you
must memorize!

Polyatomic Ions

• Common Polyatomic Ions:
Name

Formula

Name

Formula

nitrate

NO3-1

chromate

CrO4-2

chlorate

ClO3-1

phospite

PO3-3

sulfate

SO4-2

phosphate

PO4-3

carbonate

CO3-2

acetate

C2H3O2-1

hydroxide

OH -1

cyanide

CN-1

ammonium

NH4+1

sulfite

SO3-2

What are Polyatomic Ions?
• A group of two or more atoms that have a
particular charge to them
• No naming rules exist, you must memorize
their names and charge
• Polyatomic Ions
nitrate
NO
chromate
CrO
ClO
phospite
PO
you must memorize: chlorate
sulfate
SO
phosphate PO
Name

Formula

Name

Formula

carbonate

-1
3
-1
3
-2
4
CO3-2

acetate

C2H3O2-1

hydroxide

OH -1

cyanide

CN-1

sulfite

SO3-2

ammonium NH4+1

-2
4
-3
3
-3
4

Practice:

Write the formula and charge for each polyatomic ion
below:
1) hydroxide

Answer: OH-

2) nitrate

Answer: NO3-

3) phosphate

Answer: PO4-3

4) sulfate

Answer: SO4-2

Ionic Compounds with Polyatomic Ions
• Naming ionic compounds that contain polyatomic
ions is very similar to naming ionic compounds
• For example, the compound NaOH contains the
cation, Sodium (Na+1) and the polyatomic ion
hydroxide (OH-1)
• Remember, when Ionic compounds come together,
their charges must always be neutral or ZERO
• Just like ionic compounds, we write the cation first
and the anion second; giving us the compound
Sodium Hydroxide--NaOH

Ionic Compounds with Polyatomic Ions
• Let us look at the compound ammonium nitrate
NH4NO3 (a very explosive chemical)
• Ammonium Nitrate is made up of 2 polyatomic
ions Ammonium (NH4+ ) & Nitrate (NO3-)
• When two polyatomic ions come together, a
neutral compound NH4NO3 forms between them
• Notice, the cation is named first, and anion
second

Ionic Compounds with Polyatomic Ions
• Consider Silver (I) Nitrate: AgNO3
• The Silver (Ag+1) cation comes first, and the polyatomic
anion Nitrate (NO3-1) comes second
• Just like in ionic compounds, the charges need to be
neutral
• The Silver cation Ag+ with a plus one charge is balanced
by the negatively charged polyatomic ion NO3-1 with a
negative one charge
• It is important to realize that because Silver (Ag) is a
transition metal it takes on multiple charges, therefore we
still use roman numerals to illustrate charge
• Therefore we write: Silver (I) Nitrate

Ionic Compounds with Polyatomic Ions
• Consider one more compound: Mg(OH)2
• The Mg+2 cation comes first, and the negative polyatomic
OH- anion comes second
• Just like in ionic compounds, the charges need to be
neutral
• Mg+2 needs be balanced by 2 negatively charged
polyatomic ions OH( )2 when more than one polyatomic
• In the case of Mg(OH)
ion exists, we put PARENTHESIS around them
• By putting parenthesis around (OH)2 and a subscript of 2,
this tells us we have 2 oxygen atoms and 2 hydrogen
atoms

What are Ionic Compounds
with Polyatomic Ions?
• Neutrally charged Compounds that contain a
polyatomic ion
• When more than one polyatomic ion exists in a
compound we put parenthesis around them
• Ex: Mg(OH)2 & AgNO3

Practice:

Write the names for the following compounds below:
1) NaOH

Answer: Sodium Hydroxide

2) Ba(OH)2

Answer: Barium Hydroxide

3) NH4Cl

Answer: Ammonium Chloride

4) AgNO3

Answer: Silver (I) Nitrate

5) CaCO3

Answer: Calcium Carbonate

6) Mg(NO3)2

Answer: Magnesium Nitrate

For assistance,
look back at the
rules for naming
Ionic Compounds

Practice:

Write the formulas for the following compounds below:
1) Calcium Hydroxide

Answer: Ca(OH)2

2) Magnesium Sulfate

Answer: MgSO4

3) Aluminum Phosphate

Answer: AlPO4

4) Ammonium Hydroxide

Answer: NH4OH

5) Iron (II) Sulfate

Answer: FeSO4

6) Calcium Phosphate

Answer: Ca3(PO4)2

For assistance,
look back at the
rules for naming
Ionic Compounds

Summarize:
(you can always write you own)
• Explain the difference between a Ionic Compound and a Covalent
Compound:
• What numbers do the following prefixes represent: tetra-, tri-, penta- ,
hexa• Write down the polyatomic ions you need to memorize, arrange them in
order according to their charge:
• Explain how we name polyatomic compounds:
• Explain how we write formulas for polyatomic compounds:
• What do we do if more than one polyatomic ion is present in a
compound?


Slide 12

UNIT: Nomenclature
TOPIC: Covalent and Polyatomic Compounds
Objectives: Lesson 2 of 3
• You will learn what a Covalent Compound is
• You will learn how to write the formulas and names for Covalent
Compounds
• You will learn and hopefully memorize the most common
polyatomic ions
• You will also learn how to write formulas and names of polyatomic
compounds

Quickwrite
In 1-2 sentences answer one of the questions below:
• Consider the Compound CO2, how is this compound
different from NaCl (hint: look at their location on the periodic
table)???

• Why do you think we use prefixes such as “tri-” on
words like triceratops, tricycle or tripod?

Covalent Compounds

•• Earlier
learned
about
Notice,we
that
the electrons
Ionic Compounds which
are not
transferred,
form
between
cationsBUT,
instead,metals)
they are
shared
(usually
and
anions
(usually
a nonbetween
the two
atoms
metals)
•• Covalent
As a result,
Covalent
Compounds
Compounds
DOorNOT
have
form
when two
more
non-metal
elements
charges like
Ionic
share
electrons
Compounds
• Recall that Hydrogen is
• classified
Therefore,
use a
aswe
a non-metal
on
the periodic
table
completely
different
• The
simplest
covalent
naming
system
when
compound is Hydrogen
writing
gas
or H2their chemical

formulas and names

H2 - Covalent Compound

Cations+

(usually metals)

-

-

+

What is a Covalent Compound?
• A compound formed between two non-metals
that involves the sharing of electrons
• Example: CO, Carbon Monoxide

Covalent Compounds:
• When naming covalent compounds there are certain steps you must follow
• These steps will help you throughout this unit and the rest of the course:

1. The first element in the formula is named first,
and the full element name is used
2. The 2nd element is named as though it were an anion (add –ide)
3. Prefixes (mono- 1, di- 2, tri- 3) are used to denote
the numbers of atoms

4. The prefix mono- is never used for naming the first element

Prefixes
Prefix

Example

mono- (one)

CO

- carbon monoxide

di- (two)

CO2 - carbon dioxide

tri- (three)

N2O3 - dinitrogen trioxide

tetra- (four)

CCl4 - carbon tetrachloride

penta- (five)

N2O5 - dinitrogen pentoxide

hexa- (six)

UF6 - uranium hexafluoride

Covalent Compounds:
• Write the name for the covalent compound CO Carbon Monoxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Carbon” for Carbon Monoxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in CO is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: Since there is 1 oxygen atom we would use the prefix mono- for Monoxide
4. The prefix mono- is never used for naming the first element
For Example: CO is called Carbon Monoxide NOT Monocarbon Monoxide

Covalent Compounds:
• Write the name for the covalent compound SO3
Sulfur Trioxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Sulfur” for Sulfur Trioxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in SO3 is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: Since there are 3 oxygen atoms we would use the prefix tri- for Trioxide
4. The prefix mono- is never used for naming the first element
For Example: SO3 is called Sulfur Trioxide NOT Monosulfur Trioxide

Covalent Compounds:
• Write the name for the covalent compound
N2O5 - Dinitrogen Pentaoxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Nitrogen” for Dinitrogen Pentaoxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in N2O5 is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: there are 5 oxygen atoms so we would use the prefix penta- for Pentaoxide
4. The prefix mono- is never used for naming the first element
For Example: Since their are 2 nitrogen atoms, we use the prefix di- for Dinitrogen

What are the Steps for
Covalent Compounds?
1. The first element in the formula is named first, and the full
element name is used
2. The 2nd element is named as though it were an anion
3. Prefixes are used to denote the numbers of atomsmono- 1, di- 2, tri- 3, tetra- 4, penta- 5, hexa- 6
4. The prefix mono- is never used for naming the first element

Practice:

Write the names for the following compounds below:
1) SF6

Answer: Sulfur Hexafluoride

2) PCl5

Answer: Phosphorous Pentachloride

3) N2O4

Answer: Dinitrogen Tetraoxide

4) CCl4

Answer: Carbon Tetrachloride

5) CO2

Answer: Carbon Dioxide

6) NO2

Answer: Nitrogen Dioxide

Practice:

Write the formulas for the following compounds below:
1) Dinitrogen Dioxide

Answer: N2O2

2) Sulfur Trioxide

Answer: SO3

3) Diphosphorous Pentaoxide Answer: P2O5
4) Nitrogen Monoxide

Answer: NO

5) Carbon Tetrafluoride

Answer: CF4

6) Silcon Dioxide

Answer: SiO2

Polyatomic Ions

• Polyatomic Ions are a group of two or more atoms
that have a particular charge to them
+1
• An example would include the ammonium ion

[

+
]

• It is composed of
atom and
atoms which give it a +1 charge
• These ions are assigned special names that you
must memorize!

Polyatomic Ions

• Common Polyatomic Ions:
Name

Formula

Name

Formula

nitrate

NO3-1

chromate

CrO4-2

chlorate

ClO3-1

phospite

PO3-3

sulfate

SO4-2

phosphate

PO4-3

carbonate

CO3-2

acetate

C2H3O2-1

hydroxide

OH -1

cyanide

CN-1

ammonium

NH4+1

sulfite

SO3-2

What are Polyatomic Ions?
• A group of two or more atoms that have a
particular charge to them
• No naming rules exist, you must memorize
their names and charge
• Polyatomic Ions
nitrate
NO
chromate
CrO
ClO
phospite
PO
you must memorize: chlorate
sulfate
SO
phosphate PO
Name

Formula

Name

Formula

carbonate

-1
3
-1
3
-2
4
CO3-2

acetate

C2H3O2-1

hydroxide

OH -1

cyanide

CN-1

sulfite

SO3-2

ammonium NH4+1

-2
4
-3
3
-3
4

Practice:

Write the formula and charge for each polyatomic ion
below:
1) hydroxide

Answer: OH-

2) nitrate

Answer: NO3-

3) phosphate

Answer: PO4-3

4) sulfate

Answer: SO4-2

Ionic Compounds with Polyatomic Ions
• Naming ionic compounds that contain polyatomic
ions is very similar to naming ionic compounds
• For example, the compound NaOH contains the
cation, Sodium (Na+1) and the polyatomic ion
hydroxide (OH-1)
• Remember, when Ionic compounds come together,
their charges must always be neutral or ZERO
• Just like ionic compounds, we write the cation first
and the anion second; giving us the compound
Sodium Hydroxide--NaOH

Ionic Compounds with Polyatomic Ions
• Let us look at the compound ammonium nitrate
NH4NO3 (a very explosive chemical)
• Ammonium Nitrate is made up of 2 polyatomic
ions Ammonium (NH4+ ) & Nitrate (NO3-)
• When two polyatomic ions come together, a
neutral compound NH4NO3 forms between them
• Notice, the cation is named first, and anion
second

Ionic Compounds with Polyatomic Ions
• Consider Silver (I) Nitrate: AgNO3
• The Silver (Ag+1) cation comes first, and the polyatomic
anion Nitrate (NO3-1) comes second
• Just like in ionic compounds, the charges need to be
neutral
• The Silver cation Ag+ with a plus one charge is balanced
by the negatively charged polyatomic ion NO3-1 with a
negative one charge
• It is important to realize that because Silver (Ag) is a
transition metal it takes on multiple charges, therefore we
still use roman numerals to illustrate charge
• Therefore we write: Silver (I) Nitrate

Ionic Compounds with Polyatomic Ions
• Consider one more compound: Mg(OH)2
• The Mg+2 cation comes first, and the negative polyatomic
OH- anion comes second
• Just like in ionic compounds, the charges need to be
neutral
• Mg+2 needs be balanced by 2 negatively charged
polyatomic ions OH( )2 when more than one polyatomic
• In the case of Mg(OH)
ion exists, we put PARENTHESIS around them
• By putting parenthesis around (OH)2 and a subscript of 2,
this tells us we have 2 oxygen atoms and 2 hydrogen
atoms

What are Ionic Compounds
with Polyatomic Ions?
• Neutrally charged Compounds that contain a
polyatomic ion
• When more than one polyatomic ion exists in a
compound we put parenthesis around them
• Ex: Mg(OH)2 & AgNO3

Practice:

Write the names for the following compounds below:
1) NaOH

Answer: Sodium Hydroxide

2) Ba(OH)2

Answer: Barium Hydroxide

3) NH4Cl

Answer: Ammonium Chloride

4) AgNO3

Answer: Silver (I) Nitrate

5) CaCO3

Answer: Calcium Carbonate

6) Mg(NO3)2

Answer: Magnesium Nitrate

For assistance,
look back at the
rules for naming
Ionic Compounds

Practice:

Write the formulas for the following compounds below:
1) Calcium Hydroxide

Answer: Ca(OH)2

2) Magnesium Sulfate

Answer: MgSO4

3) Aluminum Phosphate

Answer: AlPO4

4) Ammonium Hydroxide

Answer: NH4OH

5) Iron (II) Sulfate

Answer: FeSO4

6) Calcium Phosphate

Answer: Ca3(PO4)2

For assistance,
look back at the
rules for naming
Ionic Compounds

Summarize:
(you can always write you own)
• Explain the difference between a Ionic Compound and a Covalent
Compound:
• What numbers do the following prefixes represent: tetra-, tri-, penta- ,
hexa• Write down the polyatomic ions you need to memorize, arrange them in
order according to their charge:
• Explain how we name polyatomic compounds:
• Explain how we write formulas for polyatomic compounds:
• What do we do if more than one polyatomic ion is present in a
compound?


Slide 13

UNIT: Nomenclature
TOPIC: Covalent and Polyatomic Compounds
Objectives: Lesson 2 of 3
• You will learn what a Covalent Compound is
• You will learn how to write the formulas and names for Covalent
Compounds
• You will learn and hopefully memorize the most common
polyatomic ions
• You will also learn how to write formulas and names of polyatomic
compounds

Quickwrite
In 1-2 sentences answer one of the questions below:
• Consider the Compound CO2, how is this compound
different from NaCl (hint: look at their location on the periodic
table)???

• Why do you think we use prefixes such as “tri-” on
words like triceratops, tricycle or tripod?

Covalent Compounds

•• Earlier
learned
about
Notice,we
that
the electrons
Ionic Compounds which
are not
transferred,
form
between
cationsBUT,
instead,metals)
they are
shared
(usually
and
anions
(usually
a nonbetween
the two
atoms
metals)
•• Covalent
As a result,
Covalent
Compounds
Compounds
DOorNOT
have
form
when two
more
non-metal
elements
charges like
Ionic
share
electrons
Compounds
• Recall that Hydrogen is
• classified
Therefore,
use a
aswe
a non-metal
on
the periodic
table
completely
different
• The
simplest
covalent
naming
system
when
compound is Hydrogen
writing
gas
or H2their chemical

formulas and names

H2 - Covalent Compound

Cations+

(usually metals)

-

-

+

What is a Covalent Compound?
• A compound formed between two non-metals
that involves the sharing of electrons
• Example: CO, Carbon Monoxide

Covalent Compounds:
• When naming covalent compounds there are certain steps you must follow
• These steps will help you throughout this unit and the rest of the course:

1. The first element in the formula is named first,
and the full element name is used
2. The 2nd element is named as though it were an anion (add –ide)
3. Prefixes (mono- 1, di- 2, tri- 3) are used to denote
the numbers of atoms

4. The prefix mono- is never used for naming the first element

Prefixes
Prefix

Example

mono- (one)

CO

- carbon monoxide

di- (two)

CO2 - carbon dioxide

tri- (three)

N2O3 - dinitrogen trioxide

tetra- (four)

CCl4 - carbon tetrachloride

penta- (five)

N2O5 - dinitrogen pentoxide

hexa- (six)

UF6 - uranium hexafluoride

Covalent Compounds:
• Write the name for the covalent compound CO Carbon Monoxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Carbon” for Carbon Monoxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in CO is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: Since there is 1 oxygen atom we would use the prefix mono- for Monoxide
4. The prefix mono- is never used for naming the first element
For Example: CO is called Carbon Monoxide NOT Monocarbon Monoxide

Covalent Compounds:
• Write the name for the covalent compound SO3
Sulfur Trioxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Sulfur” for Sulfur Trioxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in SO3 is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: Since there are 3 oxygen atoms we would use the prefix tri- for Trioxide
4. The prefix mono- is never used for naming the first element
For Example: SO3 is called Sulfur Trioxide NOT Monosulfur Trioxide

Covalent Compounds:
• Write the name for the covalent compound
N2O5 - Dinitrogen Pentaoxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Nitrogen” for Dinitrogen Pentaoxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in N2O5 is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: there are 5 oxygen atoms so we would use the prefix penta- for Pentaoxide
4. The prefix mono- is never used for naming the first element
For Example: Since their are 2 nitrogen atoms, we use the prefix di- for Dinitrogen

What are the Steps for
Covalent Compounds?
1. The first element in the formula is named first, and the full
element name is used
2. The 2nd element is named as though it were an anion
3. Prefixes are used to denote the numbers of atomsmono- 1, di- 2, tri- 3, tetra- 4, penta- 5, hexa- 6
4. The prefix mono- is never used for naming the first element

Practice:

Write the names for the following compounds below:
1) SF6

Answer: Sulfur Hexafluoride

2) PCl5

Answer: Phosphorous Pentachloride

3) N2O4

Answer: Dinitrogen Tetraoxide

4) CCl4

Answer: Carbon Tetrachloride

5) CO2

Answer: Carbon Dioxide

6) NO2

Answer: Nitrogen Dioxide

Practice:

Write the formulas for the following compounds below:
1) Dinitrogen Dioxide

Answer: N2O2

2) Sulfur Trioxide

Answer: SO3

3) Diphosphorous Pentaoxide Answer: P2O5
4) Nitrogen Monoxide

Answer: NO

5) Carbon Tetrafluoride

Answer: CF4

6) Silcon Dioxide

Answer: SiO2

Polyatomic Ions

• Polyatomic Ions are a group of two or more atoms
that have a particular charge to them
+1
• An example would include the ammonium ion

[

+
]

• It is composed of
atom and
atoms which give it a +1 charge
• These ions are assigned special names that you
must memorize!

Polyatomic Ions

• Common Polyatomic Ions:
Name

Formula

Name

Formula

nitrate

NO3-1

chromate

CrO4-2

chlorate

ClO3-1

phospite

PO3-3

sulfate

SO4-2

phosphate

PO4-3

carbonate

CO3-2

acetate

C2H3O2-1

hydroxide

OH -1

cyanide

CN-1

ammonium

NH4+1

sulfite

SO3-2

What are Polyatomic Ions?
• A group of two or more atoms that have a
particular charge to them
• No naming rules exist, you must memorize
their names and charge
• Polyatomic Ions
nitrate
NO
chromate
CrO
ClO
phospite
PO
you must memorize: chlorate
sulfate
SO
phosphate PO
Name

Formula

Name

Formula

carbonate

-1
3
-1
3
-2
4
CO3-2

acetate

C2H3O2-1

hydroxide

OH -1

cyanide

CN-1

sulfite

SO3-2

ammonium NH4+1

-2
4
-3
3
-3
4

Practice:

Write the formula and charge for each polyatomic ion
below:
1) hydroxide

Answer: OH-

2) nitrate

Answer: NO3-

3) phosphate

Answer: PO4-3

4) sulfate

Answer: SO4-2

Ionic Compounds with Polyatomic Ions
• Naming ionic compounds that contain polyatomic
ions is very similar to naming ionic compounds
• For example, the compound NaOH contains the
cation, Sodium (Na+1) and the polyatomic ion
hydroxide (OH-1)
• Remember, when Ionic compounds come together,
their charges must always be neutral or ZERO
• Just like ionic compounds, we write the cation first
and the anion second; giving us the compound
Sodium Hydroxide--NaOH

Ionic Compounds with Polyatomic Ions
• Let us look at the compound ammonium nitrate
NH4NO3 (a very explosive chemical)
• Ammonium Nitrate is made up of 2 polyatomic
ions Ammonium (NH4+ ) & Nitrate (NO3-)
• When two polyatomic ions come together, a
neutral compound NH4NO3 forms between them
• Notice, the cation is named first, and anion
second

Ionic Compounds with Polyatomic Ions
• Consider Silver (I) Nitrate: AgNO3
• The Silver (Ag+1) cation comes first, and the polyatomic
anion Nitrate (NO3-1) comes second
• Just like in ionic compounds, the charges need to be
neutral
• The Silver cation Ag+ with a plus one charge is balanced
by the negatively charged polyatomic ion NO3-1 with a
negative one charge
• It is important to realize that because Silver (Ag) is a
transition metal it takes on multiple charges, therefore we
still use roman numerals to illustrate charge
• Therefore we write: Silver (I) Nitrate

Ionic Compounds with Polyatomic Ions
• Consider one more compound: Mg(OH)2
• The Mg+2 cation comes first, and the negative polyatomic
OH- anion comes second
• Just like in ionic compounds, the charges need to be
neutral
• Mg+2 needs be balanced by 2 negatively charged
polyatomic ions OH( )2 when more than one polyatomic
• In the case of Mg(OH)
ion exists, we put PARENTHESIS around them
• By putting parenthesis around (OH)2 and a subscript of 2,
this tells us we have 2 oxygen atoms and 2 hydrogen
atoms

What are Ionic Compounds
with Polyatomic Ions?
• Neutrally charged Compounds that contain a
polyatomic ion
• When more than one polyatomic ion exists in a
compound we put parenthesis around them
• Ex: Mg(OH)2 & AgNO3

Practice:

Write the names for the following compounds below:
1) NaOH

Answer: Sodium Hydroxide

2) Ba(OH)2

Answer: Barium Hydroxide

3) NH4Cl

Answer: Ammonium Chloride

4) AgNO3

Answer: Silver (I) Nitrate

5) CaCO3

Answer: Calcium Carbonate

6) Mg(NO3)2

Answer: Magnesium Nitrate

For assistance,
look back at the
rules for naming
Ionic Compounds

Practice:

Write the formulas for the following compounds below:
1) Calcium Hydroxide

Answer: Ca(OH)2

2) Magnesium Sulfate

Answer: MgSO4

3) Aluminum Phosphate

Answer: AlPO4

4) Ammonium Hydroxide

Answer: NH4OH

5) Iron (II) Sulfate

Answer: FeSO4

6) Calcium Phosphate

Answer: Ca3(PO4)2

For assistance,
look back at the
rules for naming
Ionic Compounds

Summarize:
(you can always write you own)
• Explain the difference between a Ionic Compound and a Covalent
Compound:
• What numbers do the following prefixes represent: tetra-, tri-, penta- ,
hexa• Write down the polyatomic ions you need to memorize, arrange them in
order according to their charge:
• Explain how we name polyatomic compounds:
• Explain how we write formulas for polyatomic compounds:
• What do we do if more than one polyatomic ion is present in a
compound?


Slide 14

UNIT: Nomenclature
TOPIC: Covalent and Polyatomic Compounds
Objectives: Lesson 2 of 3
• You will learn what a Covalent Compound is
• You will learn how to write the formulas and names for Covalent
Compounds
• You will learn and hopefully memorize the most common
polyatomic ions
• You will also learn how to write formulas and names of polyatomic
compounds

Quickwrite
In 1-2 sentences answer one of the questions below:
• Consider the Compound CO2, how is this compound
different from NaCl (hint: look at their location on the periodic
table)???

• Why do you think we use prefixes such as “tri-” on
words like triceratops, tricycle or tripod?

Covalent Compounds

•• Earlier
learned
about
Notice,we
that
the electrons
Ionic Compounds which
are not
transferred,
form
between
cationsBUT,
instead,metals)
they are
shared
(usually
and
anions
(usually
a nonbetween
the two
atoms
metals)
•• Covalent
As a result,
Covalent
Compounds
Compounds
DOorNOT
have
form
when two
more
non-metal
elements
charges like
Ionic
share
electrons
Compounds
• Recall that Hydrogen is
• classified
Therefore,
use a
aswe
a non-metal
on
the periodic
table
completely
different
• The
simplest
covalent
naming
system
when
compound is Hydrogen
writing
gas
or H2their chemical

formulas and names

H2 - Covalent Compound

Cations+

(usually metals)

-

-

+

What is a Covalent Compound?
• A compound formed between two non-metals
that involves the sharing of electrons
• Example: CO, Carbon Monoxide

Covalent Compounds:
• When naming covalent compounds there are certain steps you must follow
• These steps will help you throughout this unit and the rest of the course:

1. The first element in the formula is named first,
and the full element name is used
2. The 2nd element is named as though it were an anion (add –ide)
3. Prefixes (mono- 1, di- 2, tri- 3) are used to denote
the numbers of atoms

4. The prefix mono- is never used for naming the first element

Prefixes
Prefix

Example

mono- (one)

CO

- carbon monoxide

di- (two)

CO2 - carbon dioxide

tri- (three)

N2O3 - dinitrogen trioxide

tetra- (four)

CCl4 - carbon tetrachloride

penta- (five)

N2O5 - dinitrogen pentoxide

hexa- (six)

UF6 - uranium hexafluoride

Covalent Compounds:
• Write the name for the covalent compound CO Carbon Monoxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Carbon” for Carbon Monoxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in CO is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: Since there is 1 oxygen atom we would use the prefix mono- for Monoxide
4. The prefix mono- is never used for naming the first element
For Example: CO is called Carbon Monoxide NOT Monocarbon Monoxide

Covalent Compounds:
• Write the name for the covalent compound SO3
Sulfur Trioxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Sulfur” for Sulfur Trioxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in SO3 is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: Since there are 3 oxygen atoms we would use the prefix tri- for Trioxide
4. The prefix mono- is never used for naming the first element
For Example: SO3 is called Sulfur Trioxide NOT Monosulfur Trioxide

Covalent Compounds:
• Write the name for the covalent compound
N2O5 - Dinitrogen Pentaoxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Nitrogen” for Dinitrogen Pentaoxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in N2O5 is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: there are 5 oxygen atoms so we would use the prefix penta- for Pentaoxide
4. The prefix mono- is never used for naming the first element
For Example: Since their are 2 nitrogen atoms, we use the prefix di- for Dinitrogen

What are the Steps for
Covalent Compounds?
1. The first element in the formula is named first, and the full
element name is used
2. The 2nd element is named as though it were an anion
3. Prefixes are used to denote the numbers of atomsmono- 1, di- 2, tri- 3, tetra- 4, penta- 5, hexa- 6
4. The prefix mono- is never used for naming the first element

Practice:

Write the names for the following compounds below:
1) SF6

Answer: Sulfur Hexafluoride

2) PCl5

Answer: Phosphorous Pentachloride

3) N2O4

Answer: Dinitrogen Tetraoxide

4) CCl4

Answer: Carbon Tetrachloride

5) CO2

Answer: Carbon Dioxide

6) NO2

Answer: Nitrogen Dioxide

Practice:

Write the formulas for the following compounds below:
1) Dinitrogen Dioxide

Answer: N2O2

2) Sulfur Trioxide

Answer: SO3

3) Diphosphorous Pentaoxide Answer: P2O5
4) Nitrogen Monoxide

Answer: NO

5) Carbon Tetrafluoride

Answer: CF4

6) Silcon Dioxide

Answer: SiO2

Polyatomic Ions

• Polyatomic Ions are a group of two or more atoms
that have a particular charge to them
+1
• An example would include the ammonium ion

[

+
]

• It is composed of
atom and
atoms which give it a +1 charge
• These ions are assigned special names that you
must memorize!

Polyatomic Ions

• Common Polyatomic Ions:
Name

Formula

Name

Formula

nitrate

NO3-1

chromate

CrO4-2

chlorate

ClO3-1

phospite

PO3-3

sulfate

SO4-2

phosphate

PO4-3

carbonate

CO3-2

acetate

C2H3O2-1

hydroxide

OH -1

cyanide

CN-1

ammonium

NH4+1

sulfite

SO3-2

What are Polyatomic Ions?
• A group of two or more atoms that have a
particular charge to them
• No naming rules exist, you must memorize
their names and charge
• Polyatomic Ions
nitrate
NO
chromate
CrO
ClO
phospite
PO
you must memorize: chlorate
sulfate
SO
phosphate PO
Name

Formula

Name

Formula

carbonate

-1
3
-1
3
-2
4
CO3-2

acetate

C2H3O2-1

hydroxide

OH -1

cyanide

CN-1

sulfite

SO3-2

ammonium NH4+1

-2
4
-3
3
-3
4

Practice:

Write the formula and charge for each polyatomic ion
below:
1) hydroxide

Answer: OH-

2) nitrate

Answer: NO3-

3) phosphate

Answer: PO4-3

4) sulfate

Answer: SO4-2

Ionic Compounds with Polyatomic Ions
• Naming ionic compounds that contain polyatomic
ions is very similar to naming ionic compounds
• For example, the compound NaOH contains the
cation, Sodium (Na+1) and the polyatomic ion
hydroxide (OH-1)
• Remember, when Ionic compounds come together,
their charges must always be neutral or ZERO
• Just like ionic compounds, we write the cation first
and the anion second; giving us the compound
Sodium Hydroxide--NaOH

Ionic Compounds with Polyatomic Ions
• Let us look at the compound ammonium nitrate
NH4NO3 (a very explosive chemical)
• Ammonium Nitrate is made up of 2 polyatomic
ions Ammonium (NH4+ ) & Nitrate (NO3-)
• When two polyatomic ions come together, a
neutral compound NH4NO3 forms between them
• Notice, the cation is named first, and anion
second

Ionic Compounds with Polyatomic Ions
• Consider Silver (I) Nitrate: AgNO3
• The Silver (Ag+1) cation comes first, and the polyatomic
anion Nitrate (NO3-1) comes second
• Just like in ionic compounds, the charges need to be
neutral
• The Silver cation Ag+ with a plus one charge is balanced
by the negatively charged polyatomic ion NO3-1 with a
negative one charge
• It is important to realize that because Silver (Ag) is a
transition metal it takes on multiple charges, therefore we
still use roman numerals to illustrate charge
• Therefore we write: Silver (I) Nitrate

Ionic Compounds with Polyatomic Ions
• Consider one more compound: Mg(OH)2
• The Mg+2 cation comes first, and the negative polyatomic
OH- anion comes second
• Just like in ionic compounds, the charges need to be
neutral
• Mg+2 needs be balanced by 2 negatively charged
polyatomic ions OH( )2 when more than one polyatomic
• In the case of Mg(OH)
ion exists, we put PARENTHESIS around them
• By putting parenthesis around (OH)2 and a subscript of 2,
this tells us we have 2 oxygen atoms and 2 hydrogen
atoms

What are Ionic Compounds
with Polyatomic Ions?
• Neutrally charged Compounds that contain a
polyatomic ion
• When more than one polyatomic ion exists in a
compound we put parenthesis around them
• Ex: Mg(OH)2 & AgNO3

Practice:

Write the names for the following compounds below:
1) NaOH

Answer: Sodium Hydroxide

2) Ba(OH)2

Answer: Barium Hydroxide

3) NH4Cl

Answer: Ammonium Chloride

4) AgNO3

Answer: Silver (I) Nitrate

5) CaCO3

Answer: Calcium Carbonate

6) Mg(NO3)2

Answer: Magnesium Nitrate

For assistance,
look back at the
rules for naming
Ionic Compounds

Practice:

Write the formulas for the following compounds below:
1) Calcium Hydroxide

Answer: Ca(OH)2

2) Magnesium Sulfate

Answer: MgSO4

3) Aluminum Phosphate

Answer: AlPO4

4) Ammonium Hydroxide

Answer: NH4OH

5) Iron (II) Sulfate

Answer: FeSO4

6) Calcium Phosphate

Answer: Ca3(PO4)2

For assistance,
look back at the
rules for naming
Ionic Compounds

Summarize:
(you can always write you own)
• Explain the difference between a Ionic Compound and a Covalent
Compound:
• What numbers do the following prefixes represent: tetra-, tri-, penta- ,
hexa• Write down the polyatomic ions you need to memorize, arrange them in
order according to their charge:
• Explain how we name polyatomic compounds:
• Explain how we write formulas for polyatomic compounds:
• What do we do if more than one polyatomic ion is present in a
compound?


Slide 15

UNIT: Nomenclature
TOPIC: Covalent and Polyatomic Compounds
Objectives: Lesson 2 of 3
• You will learn what a Covalent Compound is
• You will learn how to write the formulas and names for Covalent
Compounds
• You will learn and hopefully memorize the most common
polyatomic ions
• You will also learn how to write formulas and names of polyatomic
compounds

Quickwrite
In 1-2 sentences answer one of the questions below:
• Consider the Compound CO2, how is this compound
different from NaCl (hint: look at their location on the periodic
table)???

• Why do you think we use prefixes such as “tri-” on
words like triceratops, tricycle or tripod?

Covalent Compounds

•• Earlier
learned
about
Notice,we
that
the electrons
Ionic Compounds which
are not
transferred,
form
between
cationsBUT,
instead,metals)
they are
shared
(usually
and
anions
(usually
a nonbetween
the two
atoms
metals)
•• Covalent
As a result,
Covalent
Compounds
Compounds
DOorNOT
have
form
when two
more
non-metal
elements
charges like
Ionic
share
electrons
Compounds
• Recall that Hydrogen is
• classified
Therefore,
use a
aswe
a non-metal
on
the periodic
table
completely
different
• The
simplest
covalent
naming
system
when
compound is Hydrogen
writing
gas
or H2their chemical

formulas and names

H2 - Covalent Compound

Cations+

(usually metals)

-

-

+

What is a Covalent Compound?
• A compound formed between two non-metals
that involves the sharing of electrons
• Example: CO, Carbon Monoxide

Covalent Compounds:
• When naming covalent compounds there are certain steps you must follow
• These steps will help you throughout this unit and the rest of the course:

1. The first element in the formula is named first,
and the full element name is used
2. The 2nd element is named as though it were an anion (add –ide)
3. Prefixes (mono- 1, di- 2, tri- 3) are used to denote
the numbers of atoms

4. The prefix mono- is never used for naming the first element

Prefixes
Prefix

Example

mono- (one)

CO

- carbon monoxide

di- (two)

CO2 - carbon dioxide

tri- (three)

N2O3 - dinitrogen trioxide

tetra- (four)

CCl4 - carbon tetrachloride

penta- (five)

N2O5 - dinitrogen pentoxide

hexa- (six)

UF6 - uranium hexafluoride

Covalent Compounds:
• Write the name for the covalent compound CO Carbon Monoxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Carbon” for Carbon Monoxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in CO is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: Since there is 1 oxygen atom we would use the prefix mono- for Monoxide
4. The prefix mono- is never used for naming the first element
For Example: CO is called Carbon Monoxide NOT Monocarbon Monoxide

Covalent Compounds:
• Write the name for the covalent compound SO3
Sulfur Trioxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Sulfur” for Sulfur Trioxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in SO3 is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: Since there are 3 oxygen atoms we would use the prefix tri- for Trioxide
4. The prefix mono- is never used for naming the first element
For Example: SO3 is called Sulfur Trioxide NOT Monosulfur Trioxide

Covalent Compounds:
• Write the name for the covalent compound
N2O5 - Dinitrogen Pentaoxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Nitrogen” for Dinitrogen Pentaoxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in N2O5 is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: there are 5 oxygen atoms so we would use the prefix penta- for Pentaoxide
4. The prefix mono- is never used for naming the first element
For Example: Since their are 2 nitrogen atoms, we use the prefix di- for Dinitrogen

What are the Steps for
Covalent Compounds?
1. The first element in the formula is named first, and the full
element name is used
2. The 2nd element is named as though it were an anion
3. Prefixes are used to denote the numbers of atomsmono- 1, di- 2, tri- 3, tetra- 4, penta- 5, hexa- 6
4. The prefix mono- is never used for naming the first element

Practice:

Write the names for the following compounds below:
1) SF6

Answer: Sulfur Hexafluoride

2) PCl5

Answer: Phosphorous Pentachloride

3) N2O4

Answer: Dinitrogen Tetraoxide

4) CCl4

Answer: Carbon Tetrachloride

5) CO2

Answer: Carbon Dioxide

6) NO2

Answer: Nitrogen Dioxide

Practice:

Write the formulas for the following compounds below:
1) Dinitrogen Dioxide

Answer: N2O2

2) Sulfur Trioxide

Answer: SO3

3) Diphosphorous Pentaoxide Answer: P2O5
4) Nitrogen Monoxide

Answer: NO

5) Carbon Tetrafluoride

Answer: CF4

6) Silcon Dioxide

Answer: SiO2

Polyatomic Ions

• Polyatomic Ions are a group of two or more atoms
that have a particular charge to them
+1
• An example would include the ammonium ion

[

+
]

• It is composed of
atom and
atoms which give it a +1 charge
• These ions are assigned special names that you
must memorize!

Polyatomic Ions

• Common Polyatomic Ions:
Name

Formula

Name

Formula

nitrate

NO3-1

chromate

CrO4-2

chlorate

ClO3-1

phospite

PO3-3

sulfate

SO4-2

phosphate

PO4-3

carbonate

CO3-2

acetate

C2H3O2-1

hydroxide

OH -1

cyanide

CN-1

ammonium

NH4+1

sulfite

SO3-2

What are Polyatomic Ions?
• A group of two or more atoms that have a
particular charge to them
• No naming rules exist, you must memorize
their names and charge
• Polyatomic Ions
nitrate
NO
chromate
CrO
ClO
phospite
PO
you must memorize: chlorate
sulfate
SO
phosphate PO
Name

Formula

Name

Formula

carbonate

-1
3
-1
3
-2
4
CO3-2

acetate

C2H3O2-1

hydroxide

OH -1

cyanide

CN-1

sulfite

SO3-2

ammonium NH4+1

-2
4
-3
3
-3
4

Practice:

Write the formula and charge for each polyatomic ion
below:
1) hydroxide

Answer: OH-

2) nitrate

Answer: NO3-

3) phosphate

Answer: PO4-3

4) sulfate

Answer: SO4-2

Ionic Compounds with Polyatomic Ions
• Naming ionic compounds that contain polyatomic
ions is very similar to naming ionic compounds
• For example, the compound NaOH contains the
cation, Sodium (Na+1) and the polyatomic ion
hydroxide (OH-1)
• Remember, when Ionic compounds come together,
their charges must always be neutral or ZERO
• Just like ionic compounds, we write the cation first
and the anion second; giving us the compound
Sodium Hydroxide--NaOH

Ionic Compounds with Polyatomic Ions
• Let us look at the compound ammonium nitrate
NH4NO3 (a very explosive chemical)
• Ammonium Nitrate is made up of 2 polyatomic
ions Ammonium (NH4+ ) & Nitrate (NO3-)
• When two polyatomic ions come together, a
neutral compound NH4NO3 forms between them
• Notice, the cation is named first, and anion
second

Ionic Compounds with Polyatomic Ions
• Consider Silver (I) Nitrate: AgNO3
• The Silver (Ag+1) cation comes first, and the polyatomic
anion Nitrate (NO3-1) comes second
• Just like in ionic compounds, the charges need to be
neutral
• The Silver cation Ag+ with a plus one charge is balanced
by the negatively charged polyatomic ion NO3-1 with a
negative one charge
• It is important to realize that because Silver (Ag) is a
transition metal it takes on multiple charges, therefore we
still use roman numerals to illustrate charge
• Therefore we write: Silver (I) Nitrate

Ionic Compounds with Polyatomic Ions
• Consider one more compound: Mg(OH)2
• The Mg+2 cation comes first, and the negative polyatomic
OH- anion comes second
• Just like in ionic compounds, the charges need to be
neutral
• Mg+2 needs be balanced by 2 negatively charged
polyatomic ions OH( )2 when more than one polyatomic
• In the case of Mg(OH)
ion exists, we put PARENTHESIS around them
• By putting parenthesis around (OH)2 and a subscript of 2,
this tells us we have 2 oxygen atoms and 2 hydrogen
atoms

What are Ionic Compounds
with Polyatomic Ions?
• Neutrally charged Compounds that contain a
polyatomic ion
• When more than one polyatomic ion exists in a
compound we put parenthesis around them
• Ex: Mg(OH)2 & AgNO3

Practice:

Write the names for the following compounds below:
1) NaOH

Answer: Sodium Hydroxide

2) Ba(OH)2

Answer: Barium Hydroxide

3) NH4Cl

Answer: Ammonium Chloride

4) AgNO3

Answer: Silver (I) Nitrate

5) CaCO3

Answer: Calcium Carbonate

6) Mg(NO3)2

Answer: Magnesium Nitrate

For assistance,
look back at the
rules for naming
Ionic Compounds

Practice:

Write the formulas for the following compounds below:
1) Calcium Hydroxide

Answer: Ca(OH)2

2) Magnesium Sulfate

Answer: MgSO4

3) Aluminum Phosphate

Answer: AlPO4

4) Ammonium Hydroxide

Answer: NH4OH

5) Iron (II) Sulfate

Answer: FeSO4

6) Calcium Phosphate

Answer: Ca3(PO4)2

For assistance,
look back at the
rules for naming
Ionic Compounds

Summarize:
(you can always write you own)
• Explain the difference between a Ionic Compound and a Covalent
Compound:
• What numbers do the following prefixes represent: tetra-, tri-, penta- ,
hexa• Write down the polyatomic ions you need to memorize, arrange them in
order according to their charge:
• Explain how we name polyatomic compounds:
• Explain how we write formulas for polyatomic compounds:
• What do we do if more than one polyatomic ion is present in a
compound?


Slide 16

UNIT: Nomenclature
TOPIC: Covalent and Polyatomic Compounds
Objectives: Lesson 2 of 3
• You will learn what a Covalent Compound is
• You will learn how to write the formulas and names for Covalent
Compounds
• You will learn and hopefully memorize the most common
polyatomic ions
• You will also learn how to write formulas and names of polyatomic
compounds

Quickwrite
In 1-2 sentences answer one of the questions below:
• Consider the Compound CO2, how is this compound
different from NaCl (hint: look at their location on the periodic
table)???

• Why do you think we use prefixes such as “tri-” on
words like triceratops, tricycle or tripod?

Covalent Compounds

•• Earlier
learned
about
Notice,we
that
the electrons
Ionic Compounds which
are not
transferred,
form
between
cationsBUT,
instead,metals)
they are
shared
(usually
and
anions
(usually
a nonbetween
the two
atoms
metals)
•• Covalent
As a result,
Covalent
Compounds
Compounds
DOorNOT
have
form
when two
more
non-metal
elements
charges like
Ionic
share
electrons
Compounds
• Recall that Hydrogen is
• classified
Therefore,
use a
aswe
a non-metal
on
the periodic
table
completely
different
• The
simplest
covalent
naming
system
when
compound is Hydrogen
writing
gas
or H2their chemical

formulas and names

H2 - Covalent Compound

Cations+

(usually metals)

-

-

+

What is a Covalent Compound?
• A compound formed between two non-metals
that involves the sharing of electrons
• Example: CO, Carbon Monoxide

Covalent Compounds:
• When naming covalent compounds there are certain steps you must follow
• These steps will help you throughout this unit and the rest of the course:

1. The first element in the formula is named first,
and the full element name is used
2. The 2nd element is named as though it were an anion (add –ide)
3. Prefixes (mono- 1, di- 2, tri- 3) are used to denote
the numbers of atoms

4. The prefix mono- is never used for naming the first element

Prefixes
Prefix

Example

mono- (one)

CO

- carbon monoxide

di- (two)

CO2 - carbon dioxide

tri- (three)

N2O3 - dinitrogen trioxide

tetra- (four)

CCl4 - carbon tetrachloride

penta- (five)

N2O5 - dinitrogen pentoxide

hexa- (six)

UF6 - uranium hexafluoride

Covalent Compounds:
• Write the name for the covalent compound CO Carbon Monoxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Carbon” for Carbon Monoxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in CO is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: Since there is 1 oxygen atom we would use the prefix mono- for Monoxide
4. The prefix mono- is never used for naming the first element
For Example: CO is called Carbon Monoxide NOT Monocarbon Monoxide

Covalent Compounds:
• Write the name for the covalent compound SO3
Sulfur Trioxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Sulfur” for Sulfur Trioxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in SO3 is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: Since there are 3 oxygen atoms we would use the prefix tri- for Trioxide
4. The prefix mono- is never used for naming the first element
For Example: SO3 is called Sulfur Trioxide NOT Monosulfur Trioxide

Covalent Compounds:
• Write the name for the covalent compound
N2O5 - Dinitrogen Pentaoxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Nitrogen” for Dinitrogen Pentaoxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in N2O5 is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: there are 5 oxygen atoms so we would use the prefix penta- for Pentaoxide
4. The prefix mono- is never used for naming the first element
For Example: Since their are 2 nitrogen atoms, we use the prefix di- for Dinitrogen

What are the Steps for
Covalent Compounds?
1. The first element in the formula is named first, and the full
element name is used
2. The 2nd element is named as though it were an anion
3. Prefixes are used to denote the numbers of atomsmono- 1, di- 2, tri- 3, tetra- 4, penta- 5, hexa- 6
4. The prefix mono- is never used for naming the first element

Practice:

Write the names for the following compounds below:
1) SF6

Answer: Sulfur Hexafluoride

2) PCl5

Answer: Phosphorous Pentachloride

3) N2O4

Answer: Dinitrogen Tetraoxide

4) CCl4

Answer: Carbon Tetrachloride

5) CO2

Answer: Carbon Dioxide

6) NO2

Answer: Nitrogen Dioxide

Practice:

Write the formulas for the following compounds below:
1) Dinitrogen Dioxide

Answer: N2O2

2) Sulfur Trioxide

Answer: SO3

3) Diphosphorous Pentaoxide Answer: P2O5
4) Nitrogen Monoxide

Answer: NO

5) Carbon Tetrafluoride

Answer: CF4

6) Silcon Dioxide

Answer: SiO2

Polyatomic Ions

• Polyatomic Ions are a group of two or more atoms
that have a particular charge to them
+1
• An example would include the ammonium ion

[

+
]

• It is composed of
atom and
atoms which give it a +1 charge
• These ions are assigned special names that you
must memorize!

Polyatomic Ions

• Common Polyatomic Ions:
Name

Formula

Name

Formula

nitrate

NO3-1

chromate

CrO4-2

chlorate

ClO3-1

phospite

PO3-3

sulfate

SO4-2

phosphate

PO4-3

carbonate

CO3-2

acetate

C2H3O2-1

hydroxide

OH -1

cyanide

CN-1

ammonium

NH4+1

sulfite

SO3-2

What are Polyatomic Ions?
• A group of two or more atoms that have a
particular charge to them
• No naming rules exist, you must memorize
their names and charge
• Polyatomic Ions
nitrate
NO
chromate
CrO
ClO
phospite
PO
you must memorize: chlorate
sulfate
SO
phosphate PO
Name

Formula

Name

Formula

carbonate

-1
3
-1
3
-2
4
CO3-2

acetate

C2H3O2-1

hydroxide

OH -1

cyanide

CN-1

sulfite

SO3-2

ammonium NH4+1

-2
4
-3
3
-3
4

Practice:

Write the formula and charge for each polyatomic ion
below:
1) hydroxide

Answer: OH-

2) nitrate

Answer: NO3-

3) phosphate

Answer: PO4-3

4) sulfate

Answer: SO4-2

Ionic Compounds with Polyatomic Ions
• Naming ionic compounds that contain polyatomic
ions is very similar to naming ionic compounds
• For example, the compound NaOH contains the
cation, Sodium (Na+1) and the polyatomic ion
hydroxide (OH-1)
• Remember, when Ionic compounds come together,
their charges must always be neutral or ZERO
• Just like ionic compounds, we write the cation first
and the anion second; giving us the compound
Sodium Hydroxide--NaOH

Ionic Compounds with Polyatomic Ions
• Let us look at the compound ammonium nitrate
NH4NO3 (a very explosive chemical)
• Ammonium Nitrate is made up of 2 polyatomic
ions Ammonium (NH4+ ) & Nitrate (NO3-)
• When two polyatomic ions come together, a
neutral compound NH4NO3 forms between them
• Notice, the cation is named first, and anion
second

Ionic Compounds with Polyatomic Ions
• Consider Silver (I) Nitrate: AgNO3
• The Silver (Ag+1) cation comes first, and the polyatomic
anion Nitrate (NO3-1) comes second
• Just like in ionic compounds, the charges need to be
neutral
• The Silver cation Ag+ with a plus one charge is balanced
by the negatively charged polyatomic ion NO3-1 with a
negative one charge
• It is important to realize that because Silver (Ag) is a
transition metal it takes on multiple charges, therefore we
still use roman numerals to illustrate charge
• Therefore we write: Silver (I) Nitrate

Ionic Compounds with Polyatomic Ions
• Consider one more compound: Mg(OH)2
• The Mg+2 cation comes first, and the negative polyatomic
OH- anion comes second
• Just like in ionic compounds, the charges need to be
neutral
• Mg+2 needs be balanced by 2 negatively charged
polyatomic ions OH( )2 when more than one polyatomic
• In the case of Mg(OH)
ion exists, we put PARENTHESIS around them
• By putting parenthesis around (OH)2 and a subscript of 2,
this tells us we have 2 oxygen atoms and 2 hydrogen
atoms

What are Ionic Compounds
with Polyatomic Ions?
• Neutrally charged Compounds that contain a
polyatomic ion
• When more than one polyatomic ion exists in a
compound we put parenthesis around them
• Ex: Mg(OH)2 & AgNO3

Practice:

Write the names for the following compounds below:
1) NaOH

Answer: Sodium Hydroxide

2) Ba(OH)2

Answer: Barium Hydroxide

3) NH4Cl

Answer: Ammonium Chloride

4) AgNO3

Answer: Silver (I) Nitrate

5) CaCO3

Answer: Calcium Carbonate

6) Mg(NO3)2

Answer: Magnesium Nitrate

For assistance,
look back at the
rules for naming
Ionic Compounds

Practice:

Write the formulas for the following compounds below:
1) Calcium Hydroxide

Answer: Ca(OH)2

2) Magnesium Sulfate

Answer: MgSO4

3) Aluminum Phosphate

Answer: AlPO4

4) Ammonium Hydroxide

Answer: NH4OH

5) Iron (II) Sulfate

Answer: FeSO4

6) Calcium Phosphate

Answer: Ca3(PO4)2

For assistance,
look back at the
rules for naming
Ionic Compounds

Summarize:
(you can always write you own)
• Explain the difference between a Ionic Compound and a Covalent
Compound:
• What numbers do the following prefixes represent: tetra-, tri-, penta- ,
hexa• Write down the polyatomic ions you need to memorize, arrange them in
order according to their charge:
• Explain how we name polyatomic compounds:
• Explain how we write formulas for polyatomic compounds:
• What do we do if more than one polyatomic ion is present in a
compound?


Slide 17

UNIT: Nomenclature
TOPIC: Covalent and Polyatomic Compounds
Objectives: Lesson 2 of 3
• You will learn what a Covalent Compound is
• You will learn how to write the formulas and names for Covalent
Compounds
• You will learn and hopefully memorize the most common
polyatomic ions
• You will also learn how to write formulas and names of polyatomic
compounds

Quickwrite
In 1-2 sentences answer one of the questions below:
• Consider the Compound CO2, how is this compound
different from NaCl (hint: look at their location on the periodic
table)???

• Why do you think we use prefixes such as “tri-” on
words like triceratops, tricycle or tripod?

Covalent Compounds

•• Earlier
learned
about
Notice,we
that
the electrons
Ionic Compounds which
are not
transferred,
form
between
cationsBUT,
instead,metals)
they are
shared
(usually
and
anions
(usually
a nonbetween
the two
atoms
metals)
•• Covalent
As a result,
Covalent
Compounds
Compounds
DOorNOT
have
form
when two
more
non-metal
elements
charges like
Ionic
share
electrons
Compounds
• Recall that Hydrogen is
• classified
Therefore,
use a
aswe
a non-metal
on
the periodic
table
completely
different
• The
simplest
covalent
naming
system
when
compound is Hydrogen
writing
gas
or H2their chemical

formulas and names

H2 - Covalent Compound

Cations+

(usually metals)

-

-

+

What is a Covalent Compound?
• A compound formed between two non-metals
that involves the sharing of electrons
• Example: CO, Carbon Monoxide

Covalent Compounds:
• When naming covalent compounds there are certain steps you must follow
• These steps will help you throughout this unit and the rest of the course:

1. The first element in the formula is named first,
and the full element name is used
2. The 2nd element is named as though it were an anion (add –ide)
3. Prefixes (mono- 1, di- 2, tri- 3) are used to denote
the numbers of atoms

4. The prefix mono- is never used for naming the first element

Prefixes
Prefix

Example

mono- (one)

CO

- carbon monoxide

di- (two)

CO2 - carbon dioxide

tri- (three)

N2O3 - dinitrogen trioxide

tetra- (four)

CCl4 - carbon tetrachloride

penta- (five)

N2O5 - dinitrogen pentoxide

hexa- (six)

UF6 - uranium hexafluoride

Covalent Compounds:
• Write the name for the covalent compound CO Carbon Monoxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Carbon” for Carbon Monoxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in CO is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: Since there is 1 oxygen atom we would use the prefix mono- for Monoxide
4. The prefix mono- is never used for naming the first element
For Example: CO is called Carbon Monoxide NOT Monocarbon Monoxide

Covalent Compounds:
• Write the name for the covalent compound SO3
Sulfur Trioxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Sulfur” for Sulfur Trioxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in SO3 is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: Since there are 3 oxygen atoms we would use the prefix tri- for Trioxide
4. The prefix mono- is never used for naming the first element
For Example: SO3 is called Sulfur Trioxide NOT Monosulfur Trioxide

Covalent Compounds:
• Write the name for the covalent compound
N2O5 - Dinitrogen Pentaoxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Nitrogen” for Dinitrogen Pentaoxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in N2O5 is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: there are 5 oxygen atoms so we would use the prefix penta- for Pentaoxide
4. The prefix mono- is never used for naming the first element
For Example: Since their are 2 nitrogen atoms, we use the prefix di- for Dinitrogen

What are the Steps for
Covalent Compounds?
1. The first element in the formula is named first, and the full
element name is used
2. The 2nd element is named as though it were an anion
3. Prefixes are used to denote the numbers of atomsmono- 1, di- 2, tri- 3, tetra- 4, penta- 5, hexa- 6
4. The prefix mono- is never used for naming the first element

Practice:

Write the names for the following compounds below:
1) SF6

Answer: Sulfur Hexafluoride

2) PCl5

Answer: Phosphorous Pentachloride

3) N2O4

Answer: Dinitrogen Tetraoxide

4) CCl4

Answer: Carbon Tetrachloride

5) CO2

Answer: Carbon Dioxide

6) NO2

Answer: Nitrogen Dioxide

Practice:

Write the formulas for the following compounds below:
1) Dinitrogen Dioxide

Answer: N2O2

2) Sulfur Trioxide

Answer: SO3

3) Diphosphorous Pentaoxide Answer: P2O5
4) Nitrogen Monoxide

Answer: NO

5) Carbon Tetrafluoride

Answer: CF4

6) Silcon Dioxide

Answer: SiO2

Polyatomic Ions

• Polyatomic Ions are a group of two or more atoms
that have a particular charge to them
+1
• An example would include the ammonium ion

[

+
]

• It is composed of
atom and
atoms which give it a +1 charge
• These ions are assigned special names that you
must memorize!

Polyatomic Ions

• Common Polyatomic Ions:
Name

Formula

Name

Formula

nitrate

NO3-1

chromate

CrO4-2

chlorate

ClO3-1

phospite

PO3-3

sulfate

SO4-2

phosphate

PO4-3

carbonate

CO3-2

acetate

C2H3O2-1

hydroxide

OH -1

cyanide

CN-1

ammonium

NH4+1

sulfite

SO3-2

What are Polyatomic Ions?
• A group of two or more atoms that have a
particular charge to them
• No naming rules exist, you must memorize
their names and charge
• Polyatomic Ions
nitrate
NO
chromate
CrO
ClO
phospite
PO
you must memorize: chlorate
sulfate
SO
phosphate PO
Name

Formula

Name

Formula

carbonate

-1
3
-1
3
-2
4
CO3-2

acetate

C2H3O2-1

hydroxide

OH -1

cyanide

CN-1

sulfite

SO3-2

ammonium NH4+1

-2
4
-3
3
-3
4

Practice:

Write the formula and charge for each polyatomic ion
below:
1) hydroxide

Answer: OH-

2) nitrate

Answer: NO3-

3) phosphate

Answer: PO4-3

4) sulfate

Answer: SO4-2

Ionic Compounds with Polyatomic Ions
• Naming ionic compounds that contain polyatomic
ions is very similar to naming ionic compounds
• For example, the compound NaOH contains the
cation, Sodium (Na+1) and the polyatomic ion
hydroxide (OH-1)
• Remember, when Ionic compounds come together,
their charges must always be neutral or ZERO
• Just like ionic compounds, we write the cation first
and the anion second; giving us the compound
Sodium Hydroxide--NaOH

Ionic Compounds with Polyatomic Ions
• Let us look at the compound ammonium nitrate
NH4NO3 (a very explosive chemical)
• Ammonium Nitrate is made up of 2 polyatomic
ions Ammonium (NH4+ ) & Nitrate (NO3-)
• When two polyatomic ions come together, a
neutral compound NH4NO3 forms between them
• Notice, the cation is named first, and anion
second

Ionic Compounds with Polyatomic Ions
• Consider Silver (I) Nitrate: AgNO3
• The Silver (Ag+1) cation comes first, and the polyatomic
anion Nitrate (NO3-1) comes second
• Just like in ionic compounds, the charges need to be
neutral
• The Silver cation Ag+ with a plus one charge is balanced
by the negatively charged polyatomic ion NO3-1 with a
negative one charge
• It is important to realize that because Silver (Ag) is a
transition metal it takes on multiple charges, therefore we
still use roman numerals to illustrate charge
• Therefore we write: Silver (I) Nitrate

Ionic Compounds with Polyatomic Ions
• Consider one more compound: Mg(OH)2
• The Mg+2 cation comes first, and the negative polyatomic
OH- anion comes second
• Just like in ionic compounds, the charges need to be
neutral
• Mg+2 needs be balanced by 2 negatively charged
polyatomic ions OH( )2 when more than one polyatomic
• In the case of Mg(OH)
ion exists, we put PARENTHESIS around them
• By putting parenthesis around (OH)2 and a subscript of 2,
this tells us we have 2 oxygen atoms and 2 hydrogen
atoms

What are Ionic Compounds
with Polyatomic Ions?
• Neutrally charged Compounds that contain a
polyatomic ion
• When more than one polyatomic ion exists in a
compound we put parenthesis around them
• Ex: Mg(OH)2 & AgNO3

Practice:

Write the names for the following compounds below:
1) NaOH

Answer: Sodium Hydroxide

2) Ba(OH)2

Answer: Barium Hydroxide

3) NH4Cl

Answer: Ammonium Chloride

4) AgNO3

Answer: Silver (I) Nitrate

5) CaCO3

Answer: Calcium Carbonate

6) Mg(NO3)2

Answer: Magnesium Nitrate

For assistance,
look back at the
rules for naming
Ionic Compounds

Practice:

Write the formulas for the following compounds below:
1) Calcium Hydroxide

Answer: Ca(OH)2

2) Magnesium Sulfate

Answer: MgSO4

3) Aluminum Phosphate

Answer: AlPO4

4) Ammonium Hydroxide

Answer: NH4OH

5) Iron (II) Sulfate

Answer: FeSO4

6) Calcium Phosphate

Answer: Ca3(PO4)2

For assistance,
look back at the
rules for naming
Ionic Compounds

Summarize:
(you can always write you own)
• Explain the difference between a Ionic Compound and a Covalent
Compound:
• What numbers do the following prefixes represent: tetra-, tri-, penta- ,
hexa• Write down the polyatomic ions you need to memorize, arrange them in
order according to their charge:
• Explain how we name polyatomic compounds:
• Explain how we write formulas for polyatomic compounds:
• What do we do if more than one polyatomic ion is present in a
compound?


Slide 18

UNIT: Nomenclature
TOPIC: Covalent and Polyatomic Compounds
Objectives: Lesson 2 of 3
• You will learn what a Covalent Compound is
• You will learn how to write the formulas and names for Covalent
Compounds
• You will learn and hopefully memorize the most common
polyatomic ions
• You will also learn how to write formulas and names of polyatomic
compounds

Quickwrite
In 1-2 sentences answer one of the questions below:
• Consider the Compound CO2, how is this compound
different from NaCl (hint: look at their location on the periodic
table)???

• Why do you think we use prefixes such as “tri-” on
words like triceratops, tricycle or tripod?

Covalent Compounds

•• Earlier
learned
about
Notice,we
that
the electrons
Ionic Compounds which
are not
transferred,
form
between
cationsBUT,
instead,metals)
they are
shared
(usually
and
anions
(usually
a nonbetween
the two
atoms
metals)
•• Covalent
As a result,
Covalent
Compounds
Compounds
DOorNOT
have
form
when two
more
non-metal
elements
charges like
Ionic
share
electrons
Compounds
• Recall that Hydrogen is
• classified
Therefore,
use a
aswe
a non-metal
on
the periodic
table
completely
different
• The
simplest
covalent
naming
system
when
compound is Hydrogen
writing
gas
or H2their chemical

formulas and names

H2 - Covalent Compound

Cations+

(usually metals)

-

-

+

What is a Covalent Compound?
• A compound formed between two non-metals
that involves the sharing of electrons
• Example: CO, Carbon Monoxide

Covalent Compounds:
• When naming covalent compounds there are certain steps you must follow
• These steps will help you throughout this unit and the rest of the course:

1. The first element in the formula is named first,
and the full element name is used
2. The 2nd element is named as though it were an anion (add –ide)
3. Prefixes (mono- 1, di- 2, tri- 3) are used to denote
the numbers of atoms

4. The prefix mono- is never used for naming the first element

Prefixes
Prefix

Example

mono- (one)

CO

- carbon monoxide

di- (two)

CO2 - carbon dioxide

tri- (three)

N2O3 - dinitrogen trioxide

tetra- (four)

CCl4 - carbon tetrachloride

penta- (five)

N2O5 - dinitrogen pentoxide

hexa- (six)

UF6 - uranium hexafluoride

Covalent Compounds:
• Write the name for the covalent compound CO Carbon Monoxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Carbon” for Carbon Monoxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in CO is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: Since there is 1 oxygen atom we would use the prefix mono- for Monoxide
4. The prefix mono- is never used for naming the first element
For Example: CO is called Carbon Monoxide NOT Monocarbon Monoxide

Covalent Compounds:
• Write the name for the covalent compound SO3
Sulfur Trioxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Sulfur” for Sulfur Trioxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in SO3 is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: Since there are 3 oxygen atoms we would use the prefix tri- for Trioxide
4. The prefix mono- is never used for naming the first element
For Example: SO3 is called Sulfur Trioxide NOT Monosulfur Trioxide

Covalent Compounds:
• Write the name for the covalent compound
N2O5 - Dinitrogen Pentaoxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Nitrogen” for Dinitrogen Pentaoxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in N2O5 is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: there are 5 oxygen atoms so we would use the prefix penta- for Pentaoxide
4. The prefix mono- is never used for naming the first element
For Example: Since their are 2 nitrogen atoms, we use the prefix di- for Dinitrogen

What are the Steps for
Covalent Compounds?
1. The first element in the formula is named first, and the full
element name is used
2. The 2nd element is named as though it were an anion
3. Prefixes are used to denote the numbers of atomsmono- 1, di- 2, tri- 3, tetra- 4, penta- 5, hexa- 6
4. The prefix mono- is never used for naming the first element

Practice:

Write the names for the following compounds below:
1) SF6

Answer: Sulfur Hexafluoride

2) PCl5

Answer: Phosphorous Pentachloride

3) N2O4

Answer: Dinitrogen Tetraoxide

4) CCl4

Answer: Carbon Tetrachloride

5) CO2

Answer: Carbon Dioxide

6) NO2

Answer: Nitrogen Dioxide

Practice:

Write the formulas for the following compounds below:
1) Dinitrogen Dioxide

Answer: N2O2

2) Sulfur Trioxide

Answer: SO3

3) Diphosphorous Pentaoxide Answer: P2O5
4) Nitrogen Monoxide

Answer: NO

5) Carbon Tetrafluoride

Answer: CF4

6) Silcon Dioxide

Answer: SiO2

Polyatomic Ions

• Polyatomic Ions are a group of two or more atoms
that have a particular charge to them
+1
• An example would include the ammonium ion

[

+
]

• It is composed of
atom and
atoms which give it a +1 charge
• These ions are assigned special names that you
must memorize!

Polyatomic Ions

• Common Polyatomic Ions:
Name

Formula

Name

Formula

nitrate

NO3-1

chromate

CrO4-2

chlorate

ClO3-1

phospite

PO3-3

sulfate

SO4-2

phosphate

PO4-3

carbonate

CO3-2

acetate

C2H3O2-1

hydroxide

OH -1

cyanide

CN-1

ammonium

NH4+1

sulfite

SO3-2

What are Polyatomic Ions?
• A group of two or more atoms that have a
particular charge to them
• No naming rules exist, you must memorize
their names and charge
• Polyatomic Ions
nitrate
NO
chromate
CrO
ClO
phospite
PO
you must memorize: chlorate
sulfate
SO
phosphate PO
Name

Formula

Name

Formula

carbonate

-1
3
-1
3
-2
4
CO3-2

acetate

C2H3O2-1

hydroxide

OH -1

cyanide

CN-1

sulfite

SO3-2

ammonium NH4+1

-2
4
-3
3
-3
4

Practice:

Write the formula and charge for each polyatomic ion
below:
1) hydroxide

Answer: OH-

2) nitrate

Answer: NO3-

3) phosphate

Answer: PO4-3

4) sulfate

Answer: SO4-2

Ionic Compounds with Polyatomic Ions
• Naming ionic compounds that contain polyatomic
ions is very similar to naming ionic compounds
• For example, the compound NaOH contains the
cation, Sodium (Na+1) and the polyatomic ion
hydroxide (OH-1)
• Remember, when Ionic compounds come together,
their charges must always be neutral or ZERO
• Just like ionic compounds, we write the cation first
and the anion second; giving us the compound
Sodium Hydroxide--NaOH

Ionic Compounds with Polyatomic Ions
• Let us look at the compound ammonium nitrate
NH4NO3 (a very explosive chemical)
• Ammonium Nitrate is made up of 2 polyatomic
ions Ammonium (NH4+ ) & Nitrate (NO3-)
• When two polyatomic ions come together, a
neutral compound NH4NO3 forms between them
• Notice, the cation is named first, and anion
second

Ionic Compounds with Polyatomic Ions
• Consider Silver (I) Nitrate: AgNO3
• The Silver (Ag+1) cation comes first, and the polyatomic
anion Nitrate (NO3-1) comes second
• Just like in ionic compounds, the charges need to be
neutral
• The Silver cation Ag+ with a plus one charge is balanced
by the negatively charged polyatomic ion NO3-1 with a
negative one charge
• It is important to realize that because Silver (Ag) is a
transition metal it takes on multiple charges, therefore we
still use roman numerals to illustrate charge
• Therefore we write: Silver (I) Nitrate

Ionic Compounds with Polyatomic Ions
• Consider one more compound: Mg(OH)2
• The Mg+2 cation comes first, and the negative polyatomic
OH- anion comes second
• Just like in ionic compounds, the charges need to be
neutral
• Mg+2 needs be balanced by 2 negatively charged
polyatomic ions OH( )2 when more than one polyatomic
• In the case of Mg(OH)
ion exists, we put PARENTHESIS around them
• By putting parenthesis around (OH)2 and a subscript of 2,
this tells us we have 2 oxygen atoms and 2 hydrogen
atoms

What are Ionic Compounds
with Polyatomic Ions?
• Neutrally charged Compounds that contain a
polyatomic ion
• When more than one polyatomic ion exists in a
compound we put parenthesis around them
• Ex: Mg(OH)2 & AgNO3

Practice:

Write the names for the following compounds below:
1) NaOH

Answer: Sodium Hydroxide

2) Ba(OH)2

Answer: Barium Hydroxide

3) NH4Cl

Answer: Ammonium Chloride

4) AgNO3

Answer: Silver (I) Nitrate

5) CaCO3

Answer: Calcium Carbonate

6) Mg(NO3)2

Answer: Magnesium Nitrate

For assistance,
look back at the
rules for naming
Ionic Compounds

Practice:

Write the formulas for the following compounds below:
1) Calcium Hydroxide

Answer: Ca(OH)2

2) Magnesium Sulfate

Answer: MgSO4

3) Aluminum Phosphate

Answer: AlPO4

4) Ammonium Hydroxide

Answer: NH4OH

5) Iron (II) Sulfate

Answer: FeSO4

6) Calcium Phosphate

Answer: Ca3(PO4)2

For assistance,
look back at the
rules for naming
Ionic Compounds

Summarize:
(you can always write you own)
• Explain the difference between a Ionic Compound and a Covalent
Compound:
• What numbers do the following prefixes represent: tetra-, tri-, penta- ,
hexa• Write down the polyatomic ions you need to memorize, arrange them in
order according to their charge:
• Explain how we name polyatomic compounds:
• Explain how we write formulas for polyatomic compounds:
• What do we do if more than one polyatomic ion is present in a
compound?


Slide 19

UNIT: Nomenclature
TOPIC: Covalent and Polyatomic Compounds
Objectives: Lesson 2 of 3
• You will learn what a Covalent Compound is
• You will learn how to write the formulas and names for Covalent
Compounds
• You will learn and hopefully memorize the most common
polyatomic ions
• You will also learn how to write formulas and names of polyatomic
compounds

Quickwrite
In 1-2 sentences answer one of the questions below:
• Consider the Compound CO2, how is this compound
different from NaCl (hint: look at their location on the periodic
table)???

• Why do you think we use prefixes such as “tri-” on
words like triceratops, tricycle or tripod?

Covalent Compounds

•• Earlier
learned
about
Notice,we
that
the electrons
Ionic Compounds which
are not
transferred,
form
between
cationsBUT,
instead,metals)
they are
shared
(usually
and
anions
(usually
a nonbetween
the two
atoms
metals)
•• Covalent
As a result,
Covalent
Compounds
Compounds
DOorNOT
have
form
when two
more
non-metal
elements
charges like
Ionic
share
electrons
Compounds
• Recall that Hydrogen is
• classified
Therefore,
use a
aswe
a non-metal
on
the periodic
table
completely
different
• The
simplest
covalent
naming
system
when
compound is Hydrogen
writing
gas
or H2their chemical

formulas and names

H2 - Covalent Compound

Cations+

(usually metals)

-

-

+

What is a Covalent Compound?
• A compound formed between two non-metals
that involves the sharing of electrons
• Example: CO, Carbon Monoxide

Covalent Compounds:
• When naming covalent compounds there are certain steps you must follow
• These steps will help you throughout this unit and the rest of the course:

1. The first element in the formula is named first,
and the full element name is used
2. The 2nd element is named as though it were an anion (add –ide)
3. Prefixes (mono- 1, di- 2, tri- 3) are used to denote
the numbers of atoms

4. The prefix mono- is never used for naming the first element

Prefixes
Prefix

Example

mono- (one)

CO

- carbon monoxide

di- (two)

CO2 - carbon dioxide

tri- (three)

N2O3 - dinitrogen trioxide

tetra- (four)

CCl4 - carbon tetrachloride

penta- (five)

N2O5 - dinitrogen pentoxide

hexa- (six)

UF6 - uranium hexafluoride

Covalent Compounds:
• Write the name for the covalent compound CO Carbon Monoxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Carbon” for Carbon Monoxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in CO is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: Since there is 1 oxygen atom we would use the prefix mono- for Monoxide
4. The prefix mono- is never used for naming the first element
For Example: CO is called Carbon Monoxide NOT Monocarbon Monoxide

Covalent Compounds:
• Write the name for the covalent compound SO3
Sulfur Trioxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Sulfur” for Sulfur Trioxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in SO3 is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: Since there are 3 oxygen atoms we would use the prefix tri- for Trioxide
4. The prefix mono- is never used for naming the first element
For Example: SO3 is called Sulfur Trioxide NOT Monosulfur Trioxide

Covalent Compounds:
• Write the name for the covalent compound
N2O5 - Dinitrogen Pentaoxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Nitrogen” for Dinitrogen Pentaoxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in N2O5 is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: there are 5 oxygen atoms so we would use the prefix penta- for Pentaoxide
4. The prefix mono- is never used for naming the first element
For Example: Since their are 2 nitrogen atoms, we use the prefix di- for Dinitrogen

What are the Steps for
Covalent Compounds?
1. The first element in the formula is named first, and the full
element name is used
2. The 2nd element is named as though it were an anion
3. Prefixes are used to denote the numbers of atomsmono- 1, di- 2, tri- 3, tetra- 4, penta- 5, hexa- 6
4. The prefix mono- is never used for naming the first element

Practice:

Write the names for the following compounds below:
1) SF6

Answer: Sulfur Hexafluoride

2) PCl5

Answer: Phosphorous Pentachloride

3) N2O4

Answer: Dinitrogen Tetraoxide

4) CCl4

Answer: Carbon Tetrachloride

5) CO2

Answer: Carbon Dioxide

6) NO2

Answer: Nitrogen Dioxide

Practice:

Write the formulas for the following compounds below:
1) Dinitrogen Dioxide

Answer: N2O2

2) Sulfur Trioxide

Answer: SO3

3) Diphosphorous Pentaoxide Answer: P2O5
4) Nitrogen Monoxide

Answer: NO

5) Carbon Tetrafluoride

Answer: CF4

6) Silcon Dioxide

Answer: SiO2

Polyatomic Ions

• Polyatomic Ions are a group of two or more atoms
that have a particular charge to them
+1
• An example would include the ammonium ion

[

+
]

• It is composed of
atom and
atoms which give it a +1 charge
• These ions are assigned special names that you
must memorize!

Polyatomic Ions

• Common Polyatomic Ions:
Name

Formula

Name

Formula

nitrate

NO3-1

chromate

CrO4-2

chlorate

ClO3-1

phospite

PO3-3

sulfate

SO4-2

phosphate

PO4-3

carbonate

CO3-2

acetate

C2H3O2-1

hydroxide

OH -1

cyanide

CN-1

ammonium

NH4+1

sulfite

SO3-2

What are Polyatomic Ions?
• A group of two or more atoms that have a
particular charge to them
• No naming rules exist, you must memorize
their names and charge
• Polyatomic Ions
nitrate
NO
chromate
CrO
ClO
phospite
PO
you must memorize: chlorate
sulfate
SO
phosphate PO
Name

Formula

Name

Formula

carbonate

-1
3
-1
3
-2
4
CO3-2

acetate

C2H3O2-1

hydroxide

OH -1

cyanide

CN-1

sulfite

SO3-2

ammonium NH4+1

-2
4
-3
3
-3
4

Practice:

Write the formula and charge for each polyatomic ion
below:
1) hydroxide

Answer: OH-

2) nitrate

Answer: NO3-

3) phosphate

Answer: PO4-3

4) sulfate

Answer: SO4-2

Ionic Compounds with Polyatomic Ions
• Naming ionic compounds that contain polyatomic
ions is very similar to naming ionic compounds
• For example, the compound NaOH contains the
cation, Sodium (Na+1) and the polyatomic ion
hydroxide (OH-1)
• Remember, when Ionic compounds come together,
their charges must always be neutral or ZERO
• Just like ionic compounds, we write the cation first
and the anion second; giving us the compound
Sodium Hydroxide--NaOH

Ionic Compounds with Polyatomic Ions
• Let us look at the compound ammonium nitrate
NH4NO3 (a very explosive chemical)
• Ammonium Nitrate is made up of 2 polyatomic
ions Ammonium (NH4+ ) & Nitrate (NO3-)
• When two polyatomic ions come together, a
neutral compound NH4NO3 forms between them
• Notice, the cation is named first, and anion
second

Ionic Compounds with Polyatomic Ions
• Consider Silver (I) Nitrate: AgNO3
• The Silver (Ag+1) cation comes first, and the polyatomic
anion Nitrate (NO3-1) comes second
• Just like in ionic compounds, the charges need to be
neutral
• The Silver cation Ag+ with a plus one charge is balanced
by the negatively charged polyatomic ion NO3-1 with a
negative one charge
• It is important to realize that because Silver (Ag) is a
transition metal it takes on multiple charges, therefore we
still use roman numerals to illustrate charge
• Therefore we write: Silver (I) Nitrate

Ionic Compounds with Polyatomic Ions
• Consider one more compound: Mg(OH)2
• The Mg+2 cation comes first, and the negative polyatomic
OH- anion comes second
• Just like in ionic compounds, the charges need to be
neutral
• Mg+2 needs be balanced by 2 negatively charged
polyatomic ions OH( )2 when more than one polyatomic
• In the case of Mg(OH)
ion exists, we put PARENTHESIS around them
• By putting parenthesis around (OH)2 and a subscript of 2,
this tells us we have 2 oxygen atoms and 2 hydrogen
atoms

What are Ionic Compounds
with Polyatomic Ions?
• Neutrally charged Compounds that contain a
polyatomic ion
• When more than one polyatomic ion exists in a
compound we put parenthesis around them
• Ex: Mg(OH)2 & AgNO3

Practice:

Write the names for the following compounds below:
1) NaOH

Answer: Sodium Hydroxide

2) Ba(OH)2

Answer: Barium Hydroxide

3) NH4Cl

Answer: Ammonium Chloride

4) AgNO3

Answer: Silver (I) Nitrate

5) CaCO3

Answer: Calcium Carbonate

6) Mg(NO3)2

Answer: Magnesium Nitrate

For assistance,
look back at the
rules for naming
Ionic Compounds

Practice:

Write the formulas for the following compounds below:
1) Calcium Hydroxide

Answer: Ca(OH)2

2) Magnesium Sulfate

Answer: MgSO4

3) Aluminum Phosphate

Answer: AlPO4

4) Ammonium Hydroxide

Answer: NH4OH

5) Iron (II) Sulfate

Answer: FeSO4

6) Calcium Phosphate

Answer: Ca3(PO4)2

For assistance,
look back at the
rules for naming
Ionic Compounds

Summarize:
(you can always write you own)
• Explain the difference between a Ionic Compound and a Covalent
Compound:
• What numbers do the following prefixes represent: tetra-, tri-, penta- ,
hexa• Write down the polyatomic ions you need to memorize, arrange them in
order according to their charge:
• Explain how we name polyatomic compounds:
• Explain how we write formulas for polyatomic compounds:
• What do we do if more than one polyatomic ion is present in a
compound?


Slide 20

UNIT: Nomenclature
TOPIC: Covalent and Polyatomic Compounds
Objectives: Lesson 2 of 3
• You will learn what a Covalent Compound is
• You will learn how to write the formulas and names for Covalent
Compounds
• You will learn and hopefully memorize the most common
polyatomic ions
• You will also learn how to write formulas and names of polyatomic
compounds

Quickwrite
In 1-2 sentences answer one of the questions below:
• Consider the Compound CO2, how is this compound
different from NaCl (hint: look at their location on the periodic
table)???

• Why do you think we use prefixes such as “tri-” on
words like triceratops, tricycle or tripod?

Covalent Compounds

•• Earlier
learned
about
Notice,we
that
the electrons
Ionic Compounds which
are not
transferred,
form
between
cationsBUT,
instead,metals)
they are
shared
(usually
and
anions
(usually
a nonbetween
the two
atoms
metals)
•• Covalent
As a result,
Covalent
Compounds
Compounds
DOorNOT
have
form
when two
more
non-metal
elements
charges like
Ionic
share
electrons
Compounds
• Recall that Hydrogen is
• classified
Therefore,
use a
aswe
a non-metal
on
the periodic
table
completely
different
• The
simplest
covalent
naming
system
when
compound is Hydrogen
writing
gas
or H2their chemical

formulas and names

H2 - Covalent Compound

Cations+

(usually metals)

-

-

+

What is a Covalent Compound?
• A compound formed between two non-metals
that involves the sharing of electrons
• Example: CO, Carbon Monoxide

Covalent Compounds:
• When naming covalent compounds there are certain steps you must follow
• These steps will help you throughout this unit and the rest of the course:

1. The first element in the formula is named first,
and the full element name is used
2. The 2nd element is named as though it were an anion (add –ide)
3. Prefixes (mono- 1, di- 2, tri- 3) are used to denote
the numbers of atoms

4. The prefix mono- is never used for naming the first element

Prefixes
Prefix

Example

mono- (one)

CO

- carbon monoxide

di- (two)

CO2 - carbon dioxide

tri- (three)

N2O3 - dinitrogen trioxide

tetra- (four)

CCl4 - carbon tetrachloride

penta- (five)

N2O5 - dinitrogen pentoxide

hexa- (six)

UF6 - uranium hexafluoride

Covalent Compounds:
• Write the name for the covalent compound CO Carbon Monoxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Carbon” for Carbon Monoxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in CO is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: Since there is 1 oxygen atom we would use the prefix mono- for Monoxide
4. The prefix mono- is never used for naming the first element
For Example: CO is called Carbon Monoxide NOT Monocarbon Monoxide

Covalent Compounds:
• Write the name for the covalent compound SO3
Sulfur Trioxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Sulfur” for Sulfur Trioxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in SO3 is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: Since there are 3 oxygen atoms we would use the prefix tri- for Trioxide
4. The prefix mono- is never used for naming the first element
For Example: SO3 is called Sulfur Trioxide NOT Monosulfur Trioxide

Covalent Compounds:
• Write the name for the covalent compound
N2O5 - Dinitrogen Pentaoxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Nitrogen” for Dinitrogen Pentaoxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in N2O5 is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: there are 5 oxygen atoms so we would use the prefix penta- for Pentaoxide
4. The prefix mono- is never used for naming the first element
For Example: Since their are 2 nitrogen atoms, we use the prefix di- for Dinitrogen

What are the Steps for
Covalent Compounds?
1. The first element in the formula is named first, and the full
element name is used
2. The 2nd element is named as though it were an anion
3. Prefixes are used to denote the numbers of atomsmono- 1, di- 2, tri- 3, tetra- 4, penta- 5, hexa- 6
4. The prefix mono- is never used for naming the first element

Practice:

Write the names for the following compounds below:
1) SF6

Answer: Sulfur Hexafluoride

2) PCl5

Answer: Phosphorous Pentachloride

3) N2O4

Answer: Dinitrogen Tetraoxide

4) CCl4

Answer: Carbon Tetrachloride

5) CO2

Answer: Carbon Dioxide

6) NO2

Answer: Nitrogen Dioxide

Practice:

Write the formulas for the following compounds below:
1) Dinitrogen Dioxide

Answer: N2O2

2) Sulfur Trioxide

Answer: SO3

3) Diphosphorous Pentaoxide Answer: P2O5
4) Nitrogen Monoxide

Answer: NO

5) Carbon Tetrafluoride

Answer: CF4

6) Silcon Dioxide

Answer: SiO2

Polyatomic Ions

• Polyatomic Ions are a group of two or more atoms
that have a particular charge to them
+1
• An example would include the ammonium ion

[

+
]

• It is composed of
atom and
atoms which give it a +1 charge
• These ions are assigned special names that you
must memorize!

Polyatomic Ions

• Common Polyatomic Ions:
Name

Formula

Name

Formula

nitrate

NO3-1

chromate

CrO4-2

chlorate

ClO3-1

phospite

PO3-3

sulfate

SO4-2

phosphate

PO4-3

carbonate

CO3-2

acetate

C2H3O2-1

hydroxide

OH -1

cyanide

CN-1

ammonium

NH4+1

sulfite

SO3-2

What are Polyatomic Ions?
• A group of two or more atoms that have a
particular charge to them
• No naming rules exist, you must memorize
their names and charge
• Polyatomic Ions
nitrate
NO
chromate
CrO
ClO
phospite
PO
you must memorize: chlorate
sulfate
SO
phosphate PO
Name

Formula

Name

Formula

carbonate

-1
3
-1
3
-2
4
CO3-2

acetate

C2H3O2-1

hydroxide

OH -1

cyanide

CN-1

sulfite

SO3-2

ammonium NH4+1

-2
4
-3
3
-3
4

Practice:

Write the formula and charge for each polyatomic ion
below:
1) hydroxide

Answer: OH-

2) nitrate

Answer: NO3-

3) phosphate

Answer: PO4-3

4) sulfate

Answer: SO4-2

Ionic Compounds with Polyatomic Ions
• Naming ionic compounds that contain polyatomic
ions is very similar to naming ionic compounds
• For example, the compound NaOH contains the
cation, Sodium (Na+1) and the polyatomic ion
hydroxide (OH-1)
• Remember, when Ionic compounds come together,
their charges must always be neutral or ZERO
• Just like ionic compounds, we write the cation first
and the anion second; giving us the compound
Sodium Hydroxide--NaOH

Ionic Compounds with Polyatomic Ions
• Let us look at the compound ammonium nitrate
NH4NO3 (a very explosive chemical)
• Ammonium Nitrate is made up of 2 polyatomic
ions Ammonium (NH4+ ) & Nitrate (NO3-)
• When two polyatomic ions come together, a
neutral compound NH4NO3 forms between them
• Notice, the cation is named first, and anion
second

Ionic Compounds with Polyatomic Ions
• Consider Silver (I) Nitrate: AgNO3
• The Silver (Ag+1) cation comes first, and the polyatomic
anion Nitrate (NO3-1) comes second
• Just like in ionic compounds, the charges need to be
neutral
• The Silver cation Ag+ with a plus one charge is balanced
by the negatively charged polyatomic ion NO3-1 with a
negative one charge
• It is important to realize that because Silver (Ag) is a
transition metal it takes on multiple charges, therefore we
still use roman numerals to illustrate charge
• Therefore we write: Silver (I) Nitrate

Ionic Compounds with Polyatomic Ions
• Consider one more compound: Mg(OH)2
• The Mg+2 cation comes first, and the negative polyatomic
OH- anion comes second
• Just like in ionic compounds, the charges need to be
neutral
• Mg+2 needs be balanced by 2 negatively charged
polyatomic ions OH( )2 when more than one polyatomic
• In the case of Mg(OH)
ion exists, we put PARENTHESIS around them
• By putting parenthesis around (OH)2 and a subscript of 2,
this tells us we have 2 oxygen atoms and 2 hydrogen
atoms

What are Ionic Compounds
with Polyatomic Ions?
• Neutrally charged Compounds that contain a
polyatomic ion
• When more than one polyatomic ion exists in a
compound we put parenthesis around them
• Ex: Mg(OH)2 & AgNO3

Practice:

Write the names for the following compounds below:
1) NaOH

Answer: Sodium Hydroxide

2) Ba(OH)2

Answer: Barium Hydroxide

3) NH4Cl

Answer: Ammonium Chloride

4) AgNO3

Answer: Silver (I) Nitrate

5) CaCO3

Answer: Calcium Carbonate

6) Mg(NO3)2

Answer: Magnesium Nitrate

For assistance,
look back at the
rules for naming
Ionic Compounds

Practice:

Write the formulas for the following compounds below:
1) Calcium Hydroxide

Answer: Ca(OH)2

2) Magnesium Sulfate

Answer: MgSO4

3) Aluminum Phosphate

Answer: AlPO4

4) Ammonium Hydroxide

Answer: NH4OH

5) Iron (II) Sulfate

Answer: FeSO4

6) Calcium Phosphate

Answer: Ca3(PO4)2

For assistance,
look back at the
rules for naming
Ionic Compounds

Summarize:
(you can always write you own)
• Explain the difference between a Ionic Compound and a Covalent
Compound:
• What numbers do the following prefixes represent: tetra-, tri-, penta- ,
hexa• Write down the polyatomic ions you need to memorize, arrange them in
order according to their charge:
• Explain how we name polyatomic compounds:
• Explain how we write formulas for polyatomic compounds:
• What do we do if more than one polyatomic ion is present in a
compound?


Slide 21

UNIT: Nomenclature
TOPIC: Covalent and Polyatomic Compounds
Objectives: Lesson 2 of 3
• You will learn what a Covalent Compound is
• You will learn how to write the formulas and names for Covalent
Compounds
• You will learn and hopefully memorize the most common
polyatomic ions
• You will also learn how to write formulas and names of polyatomic
compounds

Quickwrite
In 1-2 sentences answer one of the questions below:
• Consider the Compound CO2, how is this compound
different from NaCl (hint: look at their location on the periodic
table)???

• Why do you think we use prefixes such as “tri-” on
words like triceratops, tricycle or tripod?

Covalent Compounds

•• Earlier
learned
about
Notice,we
that
the electrons
Ionic Compounds which
are not
transferred,
form
between
cationsBUT,
instead,metals)
they are
shared
(usually
and
anions
(usually
a nonbetween
the two
atoms
metals)
•• Covalent
As a result,
Covalent
Compounds
Compounds
DOorNOT
have
form
when two
more
non-metal
elements
charges like
Ionic
share
electrons
Compounds
• Recall that Hydrogen is
• classified
Therefore,
use a
aswe
a non-metal
on
the periodic
table
completely
different
• The
simplest
covalent
naming
system
when
compound is Hydrogen
writing
gas
or H2their chemical

formulas and names

H2 - Covalent Compound

Cations+

(usually metals)

-

-

+

What is a Covalent Compound?
• A compound formed between two non-metals
that involves the sharing of electrons
• Example: CO, Carbon Monoxide

Covalent Compounds:
• When naming covalent compounds there are certain steps you must follow
• These steps will help you throughout this unit and the rest of the course:

1. The first element in the formula is named first,
and the full element name is used
2. The 2nd element is named as though it were an anion (add –ide)
3. Prefixes (mono- 1, di- 2, tri- 3) are used to denote
the numbers of atoms

4. The prefix mono- is never used for naming the first element

Prefixes
Prefix

Example

mono- (one)

CO

- carbon monoxide

di- (two)

CO2 - carbon dioxide

tri- (three)

N2O3 - dinitrogen trioxide

tetra- (four)

CCl4 - carbon tetrachloride

penta- (five)

N2O5 - dinitrogen pentoxide

hexa- (six)

UF6 - uranium hexafluoride

Covalent Compounds:
• Write the name for the covalent compound CO Carbon Monoxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Carbon” for Carbon Monoxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in CO is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: Since there is 1 oxygen atom we would use the prefix mono- for Monoxide
4. The prefix mono- is never used for naming the first element
For Example: CO is called Carbon Monoxide NOT Monocarbon Monoxide

Covalent Compounds:
• Write the name for the covalent compound SO3
Sulfur Trioxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Sulfur” for Sulfur Trioxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in SO3 is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: Since there are 3 oxygen atoms we would use the prefix tri- for Trioxide
4. The prefix mono- is never used for naming the first element
For Example: SO3 is called Sulfur Trioxide NOT Monosulfur Trioxide

Covalent Compounds:
• Write the name for the covalent compound
N2O5 - Dinitrogen Pentaoxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Nitrogen” for Dinitrogen Pentaoxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in N2O5 is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: there are 5 oxygen atoms so we would use the prefix penta- for Pentaoxide
4. The prefix mono- is never used for naming the first element
For Example: Since their are 2 nitrogen atoms, we use the prefix di- for Dinitrogen

What are the Steps for
Covalent Compounds?
1. The first element in the formula is named first, and the full
element name is used
2. The 2nd element is named as though it were an anion
3. Prefixes are used to denote the numbers of atomsmono- 1, di- 2, tri- 3, tetra- 4, penta- 5, hexa- 6
4. The prefix mono- is never used for naming the first element

Practice:

Write the names for the following compounds below:
1) SF6

Answer: Sulfur Hexafluoride

2) PCl5

Answer: Phosphorous Pentachloride

3) N2O4

Answer: Dinitrogen Tetraoxide

4) CCl4

Answer: Carbon Tetrachloride

5) CO2

Answer: Carbon Dioxide

6) NO2

Answer: Nitrogen Dioxide

Practice:

Write the formulas for the following compounds below:
1) Dinitrogen Dioxide

Answer: N2O2

2) Sulfur Trioxide

Answer: SO3

3) Diphosphorous Pentaoxide Answer: P2O5
4) Nitrogen Monoxide

Answer: NO

5) Carbon Tetrafluoride

Answer: CF4

6) Silcon Dioxide

Answer: SiO2

Polyatomic Ions

• Polyatomic Ions are a group of two or more atoms
that have a particular charge to them
+1
• An example would include the ammonium ion

[

+
]

• It is composed of
atom and
atoms which give it a +1 charge
• These ions are assigned special names that you
must memorize!

Polyatomic Ions

• Common Polyatomic Ions:
Name

Formula

Name

Formula

nitrate

NO3-1

chromate

CrO4-2

chlorate

ClO3-1

phospite

PO3-3

sulfate

SO4-2

phosphate

PO4-3

carbonate

CO3-2

acetate

C2H3O2-1

hydroxide

OH -1

cyanide

CN-1

ammonium

NH4+1

sulfite

SO3-2

What are Polyatomic Ions?
• A group of two or more atoms that have a
particular charge to them
• No naming rules exist, you must memorize
their names and charge
• Polyatomic Ions
nitrate
NO
chromate
CrO
ClO
phospite
PO
you must memorize: chlorate
sulfate
SO
phosphate PO
Name

Formula

Name

Formula

carbonate

-1
3
-1
3
-2
4
CO3-2

acetate

C2H3O2-1

hydroxide

OH -1

cyanide

CN-1

sulfite

SO3-2

ammonium NH4+1

-2
4
-3
3
-3
4

Practice:

Write the formula and charge for each polyatomic ion
below:
1) hydroxide

Answer: OH-

2) nitrate

Answer: NO3-

3) phosphate

Answer: PO4-3

4) sulfate

Answer: SO4-2

Ionic Compounds with Polyatomic Ions
• Naming ionic compounds that contain polyatomic
ions is very similar to naming ionic compounds
• For example, the compound NaOH contains the
cation, Sodium (Na+1) and the polyatomic ion
hydroxide (OH-1)
• Remember, when Ionic compounds come together,
their charges must always be neutral or ZERO
• Just like ionic compounds, we write the cation first
and the anion second; giving us the compound
Sodium Hydroxide--NaOH

Ionic Compounds with Polyatomic Ions
• Let us look at the compound ammonium nitrate
NH4NO3 (a very explosive chemical)
• Ammonium Nitrate is made up of 2 polyatomic
ions Ammonium (NH4+ ) & Nitrate (NO3-)
• When two polyatomic ions come together, a
neutral compound NH4NO3 forms between them
• Notice, the cation is named first, and anion
second

Ionic Compounds with Polyatomic Ions
• Consider Silver (I) Nitrate: AgNO3
• The Silver (Ag+1) cation comes first, and the polyatomic
anion Nitrate (NO3-1) comes second
• Just like in ionic compounds, the charges need to be
neutral
• The Silver cation Ag+ with a plus one charge is balanced
by the negatively charged polyatomic ion NO3-1 with a
negative one charge
• It is important to realize that because Silver (Ag) is a
transition metal it takes on multiple charges, therefore we
still use roman numerals to illustrate charge
• Therefore we write: Silver (I) Nitrate

Ionic Compounds with Polyatomic Ions
• Consider one more compound: Mg(OH)2
• The Mg+2 cation comes first, and the negative polyatomic
OH- anion comes second
• Just like in ionic compounds, the charges need to be
neutral
• Mg+2 needs be balanced by 2 negatively charged
polyatomic ions OH( )2 when more than one polyatomic
• In the case of Mg(OH)
ion exists, we put PARENTHESIS around them
• By putting parenthesis around (OH)2 and a subscript of 2,
this tells us we have 2 oxygen atoms and 2 hydrogen
atoms

What are Ionic Compounds
with Polyatomic Ions?
• Neutrally charged Compounds that contain a
polyatomic ion
• When more than one polyatomic ion exists in a
compound we put parenthesis around them
• Ex: Mg(OH)2 & AgNO3

Practice:

Write the names for the following compounds below:
1) NaOH

Answer: Sodium Hydroxide

2) Ba(OH)2

Answer: Barium Hydroxide

3) NH4Cl

Answer: Ammonium Chloride

4) AgNO3

Answer: Silver (I) Nitrate

5) CaCO3

Answer: Calcium Carbonate

6) Mg(NO3)2

Answer: Magnesium Nitrate

For assistance,
look back at the
rules for naming
Ionic Compounds

Practice:

Write the formulas for the following compounds below:
1) Calcium Hydroxide

Answer: Ca(OH)2

2) Magnesium Sulfate

Answer: MgSO4

3) Aluminum Phosphate

Answer: AlPO4

4) Ammonium Hydroxide

Answer: NH4OH

5) Iron (II) Sulfate

Answer: FeSO4

6) Calcium Phosphate

Answer: Ca3(PO4)2

For assistance,
look back at the
rules for naming
Ionic Compounds

Summarize:
(you can always write you own)
• Explain the difference between a Ionic Compound and a Covalent
Compound:
• What numbers do the following prefixes represent: tetra-, tri-, penta- ,
hexa• Write down the polyatomic ions you need to memorize, arrange them in
order according to their charge:
• Explain how we name polyatomic compounds:
• Explain how we write formulas for polyatomic compounds:
• What do we do if more than one polyatomic ion is present in a
compound?


Slide 22

UNIT: Nomenclature
TOPIC: Covalent and Polyatomic Compounds
Objectives: Lesson 2 of 3
• You will learn what a Covalent Compound is
• You will learn how to write the formulas and names for Covalent
Compounds
• You will learn and hopefully memorize the most common
polyatomic ions
• You will also learn how to write formulas and names of polyatomic
compounds

Quickwrite
In 1-2 sentences answer one of the questions below:
• Consider the Compound CO2, how is this compound
different from NaCl (hint: look at their location on the periodic
table)???

• Why do you think we use prefixes such as “tri-” on
words like triceratops, tricycle or tripod?

Covalent Compounds

•• Earlier
learned
about
Notice,we
that
the electrons
Ionic Compounds which
are not
transferred,
form
between
cationsBUT,
instead,metals)
they are
shared
(usually
and
anions
(usually
a nonbetween
the two
atoms
metals)
•• Covalent
As a result,
Covalent
Compounds
Compounds
DOorNOT
have
form
when two
more
non-metal
elements
charges like
Ionic
share
electrons
Compounds
• Recall that Hydrogen is
• classified
Therefore,
use a
aswe
a non-metal
on
the periodic
table
completely
different
• The
simplest
covalent
naming
system
when
compound is Hydrogen
writing
gas
or H2their chemical

formulas and names

H2 - Covalent Compound

Cations+

(usually metals)

-

-

+

What is a Covalent Compound?
• A compound formed between two non-metals
that involves the sharing of electrons
• Example: CO, Carbon Monoxide

Covalent Compounds:
• When naming covalent compounds there are certain steps you must follow
• These steps will help you throughout this unit and the rest of the course:

1. The first element in the formula is named first,
and the full element name is used
2. The 2nd element is named as though it were an anion (add –ide)
3. Prefixes (mono- 1, di- 2, tri- 3) are used to denote
the numbers of atoms

4. The prefix mono- is never used for naming the first element

Prefixes
Prefix

Example

mono- (one)

CO

- carbon monoxide

di- (two)

CO2 - carbon dioxide

tri- (three)

N2O3 - dinitrogen trioxide

tetra- (four)

CCl4 - carbon tetrachloride

penta- (five)

N2O5 - dinitrogen pentoxide

hexa- (six)

UF6 - uranium hexafluoride

Covalent Compounds:
• Write the name for the covalent compound CO Carbon Monoxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Carbon” for Carbon Monoxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in CO is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: Since there is 1 oxygen atom we would use the prefix mono- for Monoxide
4. The prefix mono- is never used for naming the first element
For Example: CO is called Carbon Monoxide NOT Monocarbon Monoxide

Covalent Compounds:
• Write the name for the covalent compound SO3
Sulfur Trioxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Sulfur” for Sulfur Trioxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in SO3 is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: Since there are 3 oxygen atoms we would use the prefix tri- for Trioxide
4. The prefix mono- is never used for naming the first element
For Example: SO3 is called Sulfur Trioxide NOT Monosulfur Trioxide

Covalent Compounds:
• Write the name for the covalent compound
N2O5 - Dinitrogen Pentaoxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Nitrogen” for Dinitrogen Pentaoxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in N2O5 is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: there are 5 oxygen atoms so we would use the prefix penta- for Pentaoxide
4. The prefix mono- is never used for naming the first element
For Example: Since their are 2 nitrogen atoms, we use the prefix di- for Dinitrogen

What are the Steps for
Covalent Compounds?
1. The first element in the formula is named first, and the full
element name is used
2. The 2nd element is named as though it were an anion
3. Prefixes are used to denote the numbers of atomsmono- 1, di- 2, tri- 3, tetra- 4, penta- 5, hexa- 6
4. The prefix mono- is never used for naming the first element

Practice:

Write the names for the following compounds below:
1) SF6

Answer: Sulfur Hexafluoride

2) PCl5

Answer: Phosphorous Pentachloride

3) N2O4

Answer: Dinitrogen Tetraoxide

4) CCl4

Answer: Carbon Tetrachloride

5) CO2

Answer: Carbon Dioxide

6) NO2

Answer: Nitrogen Dioxide

Practice:

Write the formulas for the following compounds below:
1) Dinitrogen Dioxide

Answer: N2O2

2) Sulfur Trioxide

Answer: SO3

3) Diphosphorous Pentaoxide Answer: P2O5
4) Nitrogen Monoxide

Answer: NO

5) Carbon Tetrafluoride

Answer: CF4

6) Silcon Dioxide

Answer: SiO2

Polyatomic Ions

• Polyatomic Ions are a group of two or more atoms
that have a particular charge to them
+1
• An example would include the ammonium ion

[

+
]

• It is composed of
atom and
atoms which give it a +1 charge
• These ions are assigned special names that you
must memorize!

Polyatomic Ions

• Common Polyatomic Ions:
Name

Formula

Name

Formula

nitrate

NO3-1

chromate

CrO4-2

chlorate

ClO3-1

phospite

PO3-3

sulfate

SO4-2

phosphate

PO4-3

carbonate

CO3-2

acetate

C2H3O2-1

hydroxide

OH -1

cyanide

CN-1

ammonium

NH4+1

sulfite

SO3-2

What are Polyatomic Ions?
• A group of two or more atoms that have a
particular charge to them
• No naming rules exist, you must memorize
their names and charge
• Polyatomic Ions
nitrate
NO
chromate
CrO
ClO
phospite
PO
you must memorize: chlorate
sulfate
SO
phosphate PO
Name

Formula

Name

Formula

carbonate

-1
3
-1
3
-2
4
CO3-2

acetate

C2H3O2-1

hydroxide

OH -1

cyanide

CN-1

sulfite

SO3-2

ammonium NH4+1

-2
4
-3
3
-3
4

Practice:

Write the formula and charge for each polyatomic ion
below:
1) hydroxide

Answer: OH-

2) nitrate

Answer: NO3-

3) phosphate

Answer: PO4-3

4) sulfate

Answer: SO4-2

Ionic Compounds with Polyatomic Ions
• Naming ionic compounds that contain polyatomic
ions is very similar to naming ionic compounds
• For example, the compound NaOH contains the
cation, Sodium (Na+1) and the polyatomic ion
hydroxide (OH-1)
• Remember, when Ionic compounds come together,
their charges must always be neutral or ZERO
• Just like ionic compounds, we write the cation first
and the anion second; giving us the compound
Sodium Hydroxide--NaOH

Ionic Compounds with Polyatomic Ions
• Let us look at the compound ammonium nitrate
NH4NO3 (a very explosive chemical)
• Ammonium Nitrate is made up of 2 polyatomic
ions Ammonium (NH4+ ) & Nitrate (NO3-)
• When two polyatomic ions come together, a
neutral compound NH4NO3 forms between them
• Notice, the cation is named first, and anion
second

Ionic Compounds with Polyatomic Ions
• Consider Silver (I) Nitrate: AgNO3
• The Silver (Ag+1) cation comes first, and the polyatomic
anion Nitrate (NO3-1) comes second
• Just like in ionic compounds, the charges need to be
neutral
• The Silver cation Ag+ with a plus one charge is balanced
by the negatively charged polyatomic ion NO3-1 with a
negative one charge
• It is important to realize that because Silver (Ag) is a
transition metal it takes on multiple charges, therefore we
still use roman numerals to illustrate charge
• Therefore we write: Silver (I) Nitrate

Ionic Compounds with Polyatomic Ions
• Consider one more compound: Mg(OH)2
• The Mg+2 cation comes first, and the negative polyatomic
OH- anion comes second
• Just like in ionic compounds, the charges need to be
neutral
• Mg+2 needs be balanced by 2 negatively charged
polyatomic ions OH( )2 when more than one polyatomic
• In the case of Mg(OH)
ion exists, we put PARENTHESIS around them
• By putting parenthesis around (OH)2 and a subscript of 2,
this tells us we have 2 oxygen atoms and 2 hydrogen
atoms

What are Ionic Compounds
with Polyatomic Ions?
• Neutrally charged Compounds that contain a
polyatomic ion
• When more than one polyatomic ion exists in a
compound we put parenthesis around them
• Ex: Mg(OH)2 & AgNO3

Practice:

Write the names for the following compounds below:
1) NaOH

Answer: Sodium Hydroxide

2) Ba(OH)2

Answer: Barium Hydroxide

3) NH4Cl

Answer: Ammonium Chloride

4) AgNO3

Answer: Silver (I) Nitrate

5) CaCO3

Answer: Calcium Carbonate

6) Mg(NO3)2

Answer: Magnesium Nitrate

For assistance,
look back at the
rules for naming
Ionic Compounds

Practice:

Write the formulas for the following compounds below:
1) Calcium Hydroxide

Answer: Ca(OH)2

2) Magnesium Sulfate

Answer: MgSO4

3) Aluminum Phosphate

Answer: AlPO4

4) Ammonium Hydroxide

Answer: NH4OH

5) Iron (II) Sulfate

Answer: FeSO4

6) Calcium Phosphate

Answer: Ca3(PO4)2

For assistance,
look back at the
rules for naming
Ionic Compounds

Summarize:
(you can always write you own)
• Explain the difference between a Ionic Compound and a Covalent
Compound:
• What numbers do the following prefixes represent: tetra-, tri-, penta- ,
hexa• Write down the polyatomic ions you need to memorize, arrange them in
order according to their charge:
• Explain how we name polyatomic compounds:
• Explain how we write formulas for polyatomic compounds:
• What do we do if more than one polyatomic ion is present in a
compound?


Slide 23

UNIT: Nomenclature
TOPIC: Covalent and Polyatomic Compounds
Objectives: Lesson 2 of 3
• You will learn what a Covalent Compound is
• You will learn how to write the formulas and names for Covalent
Compounds
• You will learn and hopefully memorize the most common
polyatomic ions
• You will also learn how to write formulas and names of polyatomic
compounds

Quickwrite
In 1-2 sentences answer one of the questions below:
• Consider the Compound CO2, how is this compound
different from NaCl (hint: look at their location on the periodic
table)???

• Why do you think we use prefixes such as “tri-” on
words like triceratops, tricycle or tripod?

Covalent Compounds

•• Earlier
learned
about
Notice,we
that
the electrons
Ionic Compounds which
are not
transferred,
form
between
cationsBUT,
instead,metals)
they are
shared
(usually
and
anions
(usually
a nonbetween
the two
atoms
metals)
•• Covalent
As a result,
Covalent
Compounds
Compounds
DOorNOT
have
form
when two
more
non-metal
elements
charges like
Ionic
share
electrons
Compounds
• Recall that Hydrogen is
• classified
Therefore,
use a
aswe
a non-metal
on
the periodic
table
completely
different
• The
simplest
covalent
naming
system
when
compound is Hydrogen
writing
gas
or H2their chemical

formulas and names

H2 - Covalent Compound

Cations+

(usually metals)

-

-

+

What is a Covalent Compound?
• A compound formed between two non-metals
that involves the sharing of electrons
• Example: CO, Carbon Monoxide

Covalent Compounds:
• When naming covalent compounds there are certain steps you must follow
• These steps will help you throughout this unit and the rest of the course:

1. The first element in the formula is named first,
and the full element name is used
2. The 2nd element is named as though it were an anion (add –ide)
3. Prefixes (mono- 1, di- 2, tri- 3) are used to denote
the numbers of atoms

4. The prefix mono- is never used for naming the first element

Prefixes
Prefix

Example

mono- (one)

CO

- carbon monoxide

di- (two)

CO2 - carbon dioxide

tri- (three)

N2O3 - dinitrogen trioxide

tetra- (four)

CCl4 - carbon tetrachloride

penta- (five)

N2O5 - dinitrogen pentoxide

hexa- (six)

UF6 - uranium hexafluoride

Covalent Compounds:
• Write the name for the covalent compound CO Carbon Monoxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Carbon” for Carbon Monoxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in CO is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: Since there is 1 oxygen atom we would use the prefix mono- for Monoxide
4. The prefix mono- is never used for naming the first element
For Example: CO is called Carbon Monoxide NOT Monocarbon Monoxide

Covalent Compounds:
• Write the name for the covalent compound SO3
Sulfur Trioxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Sulfur” for Sulfur Trioxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in SO3 is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: Since there are 3 oxygen atoms we would use the prefix tri- for Trioxide
4. The prefix mono- is never used for naming the first element
For Example: SO3 is called Sulfur Trioxide NOT Monosulfur Trioxide

Covalent Compounds:
• Write the name for the covalent compound
N2O5 - Dinitrogen Pentaoxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Nitrogen” for Dinitrogen Pentaoxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in N2O5 is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: there are 5 oxygen atoms so we would use the prefix penta- for Pentaoxide
4. The prefix mono- is never used for naming the first element
For Example: Since their are 2 nitrogen atoms, we use the prefix di- for Dinitrogen

What are the Steps for
Covalent Compounds?
1. The first element in the formula is named first, and the full
element name is used
2. The 2nd element is named as though it were an anion
3. Prefixes are used to denote the numbers of atomsmono- 1, di- 2, tri- 3, tetra- 4, penta- 5, hexa- 6
4. The prefix mono- is never used for naming the first element

Practice:

Write the names for the following compounds below:
1) SF6

Answer: Sulfur Hexafluoride

2) PCl5

Answer: Phosphorous Pentachloride

3) N2O4

Answer: Dinitrogen Tetraoxide

4) CCl4

Answer: Carbon Tetrachloride

5) CO2

Answer: Carbon Dioxide

6) NO2

Answer: Nitrogen Dioxide

Practice:

Write the formulas for the following compounds below:
1) Dinitrogen Dioxide

Answer: N2O2

2) Sulfur Trioxide

Answer: SO3

3) Diphosphorous Pentaoxide Answer: P2O5
4) Nitrogen Monoxide

Answer: NO

5) Carbon Tetrafluoride

Answer: CF4

6) Silcon Dioxide

Answer: SiO2

Polyatomic Ions

• Polyatomic Ions are a group of two or more atoms
that have a particular charge to them
+1
• An example would include the ammonium ion

[

+
]

• It is composed of
atom and
atoms which give it a +1 charge
• These ions are assigned special names that you
must memorize!

Polyatomic Ions

• Common Polyatomic Ions:
Name

Formula

Name

Formula

nitrate

NO3-1

chromate

CrO4-2

chlorate

ClO3-1

phospite

PO3-3

sulfate

SO4-2

phosphate

PO4-3

carbonate

CO3-2

acetate

C2H3O2-1

hydroxide

OH -1

cyanide

CN-1

ammonium

NH4+1

sulfite

SO3-2

What are Polyatomic Ions?
• A group of two or more atoms that have a
particular charge to them
• No naming rules exist, you must memorize
their names and charge
• Polyatomic Ions
nitrate
NO
chromate
CrO
ClO
phospite
PO
you must memorize: chlorate
sulfate
SO
phosphate PO
Name

Formula

Name

Formula

carbonate

-1
3
-1
3
-2
4
CO3-2

acetate

C2H3O2-1

hydroxide

OH -1

cyanide

CN-1

sulfite

SO3-2

ammonium NH4+1

-2
4
-3
3
-3
4

Practice:

Write the formula and charge for each polyatomic ion
below:
1) hydroxide

Answer: OH-

2) nitrate

Answer: NO3-

3) phosphate

Answer: PO4-3

4) sulfate

Answer: SO4-2

Ionic Compounds with Polyatomic Ions
• Naming ionic compounds that contain polyatomic
ions is very similar to naming ionic compounds
• For example, the compound NaOH contains the
cation, Sodium (Na+1) and the polyatomic ion
hydroxide (OH-1)
• Remember, when Ionic compounds come together,
their charges must always be neutral or ZERO
• Just like ionic compounds, we write the cation first
and the anion second; giving us the compound
Sodium Hydroxide--NaOH

Ionic Compounds with Polyatomic Ions
• Let us look at the compound ammonium nitrate
NH4NO3 (a very explosive chemical)
• Ammonium Nitrate is made up of 2 polyatomic
ions Ammonium (NH4+ ) & Nitrate (NO3-)
• When two polyatomic ions come together, a
neutral compound NH4NO3 forms between them
• Notice, the cation is named first, and anion
second

Ionic Compounds with Polyatomic Ions
• Consider Silver (I) Nitrate: AgNO3
• The Silver (Ag+1) cation comes first, and the polyatomic
anion Nitrate (NO3-1) comes second
• Just like in ionic compounds, the charges need to be
neutral
• The Silver cation Ag+ with a plus one charge is balanced
by the negatively charged polyatomic ion NO3-1 with a
negative one charge
• It is important to realize that because Silver (Ag) is a
transition metal it takes on multiple charges, therefore we
still use roman numerals to illustrate charge
• Therefore we write: Silver (I) Nitrate

Ionic Compounds with Polyatomic Ions
• Consider one more compound: Mg(OH)2
• The Mg+2 cation comes first, and the negative polyatomic
OH- anion comes second
• Just like in ionic compounds, the charges need to be
neutral
• Mg+2 needs be balanced by 2 negatively charged
polyatomic ions OH( )2 when more than one polyatomic
• In the case of Mg(OH)
ion exists, we put PARENTHESIS around them
• By putting parenthesis around (OH)2 and a subscript of 2,
this tells us we have 2 oxygen atoms and 2 hydrogen
atoms

What are Ionic Compounds
with Polyatomic Ions?
• Neutrally charged Compounds that contain a
polyatomic ion
• When more than one polyatomic ion exists in a
compound we put parenthesis around them
• Ex: Mg(OH)2 & AgNO3

Practice:

Write the names for the following compounds below:
1) NaOH

Answer: Sodium Hydroxide

2) Ba(OH)2

Answer: Barium Hydroxide

3) NH4Cl

Answer: Ammonium Chloride

4) AgNO3

Answer: Silver (I) Nitrate

5) CaCO3

Answer: Calcium Carbonate

6) Mg(NO3)2

Answer: Magnesium Nitrate

For assistance,
look back at the
rules for naming
Ionic Compounds

Practice:

Write the formulas for the following compounds below:
1) Calcium Hydroxide

Answer: Ca(OH)2

2) Magnesium Sulfate

Answer: MgSO4

3) Aluminum Phosphate

Answer: AlPO4

4) Ammonium Hydroxide

Answer: NH4OH

5) Iron (II) Sulfate

Answer: FeSO4

6) Calcium Phosphate

Answer: Ca3(PO4)2

For assistance,
look back at the
rules for naming
Ionic Compounds

Summarize:
(you can always write you own)
• Explain the difference between a Ionic Compound and a Covalent
Compound:
• What numbers do the following prefixes represent: tetra-, tri-, penta- ,
hexa• Write down the polyatomic ions you need to memorize, arrange them in
order according to their charge:
• Explain how we name polyatomic compounds:
• Explain how we write formulas for polyatomic compounds:
• What do we do if more than one polyatomic ion is present in a
compound?


Slide 24

UNIT: Nomenclature
TOPIC: Covalent and Polyatomic Compounds
Objectives: Lesson 2 of 3
• You will learn what a Covalent Compound is
• You will learn how to write the formulas and names for Covalent
Compounds
• You will learn and hopefully memorize the most common
polyatomic ions
• You will also learn how to write formulas and names of polyatomic
compounds

Quickwrite
In 1-2 sentences answer one of the questions below:
• Consider the Compound CO2, how is this compound
different from NaCl (hint: look at their location on the periodic
table)???

• Why do you think we use prefixes such as “tri-” on
words like triceratops, tricycle or tripod?

Covalent Compounds

•• Earlier
learned
about
Notice,we
that
the electrons
Ionic Compounds which
are not
transferred,
form
between
cationsBUT,
instead,metals)
they are
shared
(usually
and
anions
(usually
a nonbetween
the two
atoms
metals)
•• Covalent
As a result,
Covalent
Compounds
Compounds
DOorNOT
have
form
when two
more
non-metal
elements
charges like
Ionic
share
electrons
Compounds
• Recall that Hydrogen is
• classified
Therefore,
use a
aswe
a non-metal
on
the periodic
table
completely
different
• The
simplest
covalent
naming
system
when
compound is Hydrogen
writing
gas
or H2their chemical

formulas and names

H2 - Covalent Compound

Cations+

(usually metals)

-

-

+

What is a Covalent Compound?
• A compound formed between two non-metals
that involves the sharing of electrons
• Example: CO, Carbon Monoxide

Covalent Compounds:
• When naming covalent compounds there are certain steps you must follow
• These steps will help you throughout this unit and the rest of the course:

1. The first element in the formula is named first,
and the full element name is used
2. The 2nd element is named as though it were an anion (add –ide)
3. Prefixes (mono- 1, di- 2, tri- 3) are used to denote
the numbers of atoms

4. The prefix mono- is never used for naming the first element

Prefixes
Prefix

Example

mono- (one)

CO

- carbon monoxide

di- (two)

CO2 - carbon dioxide

tri- (three)

N2O3 - dinitrogen trioxide

tetra- (four)

CCl4 - carbon tetrachloride

penta- (five)

N2O5 - dinitrogen pentoxide

hexa- (six)

UF6 - uranium hexafluoride

Covalent Compounds:
• Write the name for the covalent compound CO Carbon Monoxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Carbon” for Carbon Monoxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in CO is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: Since there is 1 oxygen atom we would use the prefix mono- for Monoxide
4. The prefix mono- is never used for naming the first element
For Example: CO is called Carbon Monoxide NOT Monocarbon Monoxide

Covalent Compounds:
• Write the name for the covalent compound SO3
Sulfur Trioxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Sulfur” for Sulfur Trioxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in SO3 is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: Since there are 3 oxygen atoms we would use the prefix tri- for Trioxide
4. The prefix mono- is never used for naming the first element
For Example: SO3 is called Sulfur Trioxide NOT Monosulfur Trioxide

Covalent Compounds:
• Write the name for the covalent compound
N2O5 - Dinitrogen Pentaoxide
1. The first element in the formula is named first, and the full element name is used
For Example: we just say “Nitrogen” for Dinitrogen Pentaoxide
2. The 2nd element is named as though it were an anion
For Example: the Oxygen in N2O5 is oxide
3. Prefixes are used to denote the numbers of atomsFor Example: there are 5 oxygen atoms so we would use the prefix penta- for Pentaoxide
4. The prefix mono- is never used for naming the first element
For Example: Since their are 2 nitrogen atoms, we use the prefix di- for Dinitrogen

What are the Steps for
Covalent Compounds?
1. The first element in the formula is named first, and the full
element name is used
2. The 2nd element is named as though it were an anion
3. Prefixes are used to denote the numbers of atomsmono- 1, di- 2, tri- 3, tetra- 4, penta- 5, hexa- 6
4. The prefix mono- is never used for naming the first element

Practice:

Write the names for the following compounds below:
1) SF6

Answer: Sulfur Hexafluoride

2) PCl5

Answer: Phosphorous Pentachloride

3) N2O4

Answer: Dinitrogen Tetraoxide

4) CCl4

Answer: Carbon Tetrachloride

5) CO2

Answer: Carbon Dioxide

6) NO2

Answer: Nitrogen Dioxide

Practice:

Write the formulas for the following compounds below:
1) Dinitrogen Dioxide

Answer: N2O2

2) Sulfur Trioxide

Answer: SO3

3) Diphosphorous Pentaoxide Answer: P2O5
4) Nitrogen Monoxide

Answer: NO

5) Carbon Tetrafluoride

Answer: CF4

6) Silcon Dioxide

Answer: SiO2

Polyatomic Ions

• Polyatomic Ions are a group of two or more atoms
that have a particular charge to them
+1
• An example would include the ammonium ion

[

+
]

• It is composed of
atom and
atoms which give it a +1 charge
• These ions are assigned special names that you
must memorize!

Polyatomic Ions

• Common Polyatomic Ions:
Name

Formula

Name

Formula

nitrate

NO3-1

chromate

CrO4-2

chlorate

ClO3-1

phospite

PO3-3

sulfate

SO4-2

phosphate

PO4-3

carbonate

CO3-2

acetate

C2H3O2-1

hydroxide

OH -1

cyanide

CN-1

ammonium

NH4+1

sulfite

SO3-2

What are Polyatomic Ions?
• A group of two or more atoms that have a
particular charge to them
• No naming rules exist, you must memorize
their names and charge
• Polyatomic Ions
nitrate
NO
chromate
CrO
ClO
phospite
PO
you must memorize: chlorate
sulfate
SO
phosphate PO
Name

Formula

Name

Formula

carbonate

-1
3
-1
3
-2
4
CO3-2

acetate

C2H3O2-1

hydroxide

OH -1

cyanide

CN-1

sulfite

SO3-2

ammonium NH4+1

-2
4
-3
3
-3
4

Practice:

Write the formula and charge for each polyatomic ion
below:
1) hydroxide

Answer: OH-

2) nitrate

Answer: NO3-

3) phosphate

Answer: PO4-3

4) sulfate

Answer: SO4-2

Ionic Compounds with Polyatomic Ions
• Naming ionic compounds that contain polyatomic
ions is very similar to naming ionic compounds
• For example, the compound NaOH contains the
cation, Sodium (Na+1) and the polyatomic ion
hydroxide (OH-1)
• Remember, when Ionic compounds come together,
their charges must always be neutral or ZERO
• Just like ionic compounds, we write the cation first
and the anion second; giving us the compound
Sodium Hydroxide--NaOH

Ionic Compounds with Polyatomic Ions
• Let us look at the compound ammonium nitrate
NH4NO3 (a very explosive chemical)
• Ammonium Nitrate is made up of 2 polyatomic
ions Ammonium (NH4+ ) & Nitrate (NO3-)
• When two polyatomic ions come together, a
neutral compound NH4NO3 forms between them
• Notice, the cation is named first, and anion
second

Ionic Compounds with Polyatomic Ions
• Consider Silver (I) Nitrate: AgNO3
• The Silver (Ag+1) cation comes first, and the polyatomic
anion Nitrate (NO3-1) comes second
• Just like in ionic compounds, the charges need to be
neutral
• The Silver cation Ag+ with a plus one charge is balanced
by the negatively charged polyatomic ion NO3-1 with a
negative one charge
• It is important to realize that because Silver (Ag) is a
transition metal it takes on multiple charges, therefore we
still use roman numerals to illustrate charge
• Therefore we write: Silver (I) Nitrate

Ionic Compounds with Polyatomic Ions
• Consider one more compound: Mg(OH)2
• The Mg+2 cation comes first, and the negative polyatomic
OH- anion comes second
• Just like in ionic compounds, the charges need to be
neutral
• Mg+2 needs be balanced by 2 negatively charged
polyatomic ions OH( )2 when more than one polyatomic
• In the case of Mg(OH)
ion exists, we put PARENTHESIS around them
• By putting parenthesis around (OH)2 and a subscript of 2,
this tells us we have 2 oxygen atoms and 2 hydrogen
atoms

What are Ionic Compounds
with Polyatomic Ions?
• Neutrally charged Compounds that contain a
polyatomic ion
• When more than one polyatomic ion exists in a
compound we put parenthesis around them
• Ex: Mg(OH)2 & AgNO3

Practice:

Write the names for the following compounds below:
1) NaOH

Answer: Sodium Hydroxide

2) Ba(OH)2

Answer: Barium Hydroxide

3) NH4Cl

Answer: Ammonium Chloride

4) AgNO3

Answer: Silver (I) Nitrate

5) CaCO3

Answer: Calcium Carbonate

6) Mg(NO3)2

Answer: Magnesium Nitrate

For assistance,
look back at the
rules for naming
Ionic Compounds

Practice:

Write the formulas for the following compounds below:
1) Calcium Hydroxide

Answer: Ca(OH)2

2) Magnesium Sulfate

Answer: MgSO4

3) Aluminum Phosphate

Answer: AlPO4

4) Ammonium Hydroxide

Answer: NH4OH

5) Iron (II) Sulfate

Answer: FeSO4

6) Calcium Phosphate

Answer: Ca3(PO4)2

For assistance,
look back at the
rules for naming
Ionic Compounds

Summarize:
(you can always write you own)
• Explain the difference between a Ionic Compound and a Covalent
Compound:
• What numbers do the following prefixes represent: tetra-, tri-, penta- ,
hexa• Write down the polyatomic ions you need to memorize, arrange them in
order according to their charge:
• Explain how we name polyatomic compounds:
• Explain how we write formulas for polyatomic compounds:
• What do we do if more than one polyatomic ion is present in a
compound?