Transcript Covalent Compounds

Covalent Compounds
Brainstorm:
What does the prefix “Co” mean?
What does covalent mean?
What types of elements do you think covalent bonds form between?
What is a covalent compound?
Covalent Compound:
◦Is a compound made up of two or more nonmetals that
are bonded together
- the electrons are shared instead of transferred
- the have NO charges
Ionic vs Covalent Compounds
IONIC
COVALENT
•Electrons are transferred from
one element to the other
•Electrons are shared not
transferred
•Occurs between a metal and a
nonmetal (cation and an anion)
•Occurs between two or more
nonmetals
Why share instead of transfer?
•Due to electronegativity
◦ Metals have very low electronegativity
◦ They do not want other atoms electrons
◦ The have a low ionization energy (meaning they do not pull hard on
their own electrons)
◦ Nonmetals have very high electronegativity
◦ They want other atoms electrons to complete their octet
◦ They pull very hard on their own, and other atoms electrons
Can you pick out the ionic vs covalent?
H2O
Na2(SO4)
MnBr2
CO2
N2O
Al(NO3)3
KCl
P2O3
NaCl
SCl2
CCl4
Li(OH)
Sr(NO2)2
BrCl5
GaN
SO2
Cs3As2
CO
H2O2
N2P3
How did you do?
H2O
Na2(SO4)
MnBr2
CO2
N2O
Al(NO3)3
KCl
P2O3
NaCl
SCl2
CCl4
Li(OH)
Sr(NO2)2
BrCl5
GaN
SO2
Cs3As2
CO
H2O2
N3P5
How to write covalent compound
formulas
• No charges to cancel out
• Several compounds can have the same elements, they just occur in different ratios.
• The specific amount of atoms in each compound is what makes it a specific compound
Examples:
CO
NO
CO2
N2O
CO3
SO
SO2
S2O3
We CANNOT and DO NOT drop and swap when writing covalent
compounds
You must know what the numerical
prefixes are
How to write covalent compound
formulas
1.Use the numerical prefix on the first element as its subscript
If no prefix it means one
No need to write 1’s.
Do NOT drop and swap
2.Use the numerical prefix on the second element as its subscript.
The prefix mono- this time means 1
No need to write 1’s.
 Do NOT drop and swap
Give it a try:
Compound Name:
Hexaboron
Monosilicide
Chlorine dioxide
Dicarbon
hexahydride
Phosphorous
triiodide
Iodine
pentafluoride
What is the first
element?
What is the
numerical value
of the prefix?
What is the
second element?
What is the
numerical value
of the prefix?
What is the
formula?
*Remember do
NOT drop and
swap.
How to name a covalent compound:
1.NEVER simplify these compounds
◦ Example: N2O4 IS NOT NO2
2.For the 1st element: Use a prefix for all numbers EXCEPT one and the elements
name off the periodic table.
◦ NO2 (Nitrogen does not need a prefix for this name)
◦ N2O (Nitrogen does need the prefix di- to indicate there are two nitrogen atoms)
3.For the 2nd element: ALWAYS use a prefix
4.For the 2nd element: Change the ending of the elements name to “-ide”
How to name a covalent compound:
C2O6
1.The first element you simply name and add the proper prefix if
needed
2.The second element you name with the proper prefix
3. For the second element change the ending to “-ide”
Dicarbon Hexaoxide
Give it a try:
Compound
Formula:
P4S5
SeF6
Si2Br6
CH4
NF3
Prefix on the
first
element:
Name of the first
element:
Prefix on the
second
element:
Name of the second
element with -ide
ending.
Name of the compound