Transcript Chapter 3
Chapter 3
Chemical Compounds
Types of Compounds
2
Inorganic Compounds – do not contain
carbon
Organic Compounds – contain carbon
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Inorganic Compounds
3
Ionic compound
combination of metals and nonmetals
made up of positive and negative ions
joined together by electrostatic
forces
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Ions
4
Ions are atoms that have either lost or gained
electrons.
Electrons are lost from the outermost energy
level (discussed later in textbook)
Ions that have more protons than electrons
are positively charged
Ions that have more electrons than protons
are negatively charged
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Monatomic Ions
Formed from a single atom
Example:
Sodium
Sulfur
5
Na+
s6+ or S2-
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Monatomic ions
6
Ions formed from a single atom
Atom = Na
Ion = Na+
Atom = O
Ion = O2-
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Using your periodic table
7
The number of the main group elements will
be used to determine the oxidation states.
Groups IA, IIA, IIIA = +, 2+, 3+
Group VA
= 5+, 3Group VIA
= 6+, 2Group VIIA
= 7+, 7/21/2015
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Alkali Metals (Group IA)
The oxidation number of alkali metals in a
compound is always 1+.
Never write the number 1 for anything in
chemistry. It is understood.
8
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Alkaline Earth Metals (Group IIA)
9
The oxidation number of alkaline earth
metals in a compound is always 2+.
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Nitrogen Family (Group VA)
Nitrides, phosphides, and arsenides are
always 3- in binary salts.
N3-
10
P3-
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As3-
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Oxygen Family (Group VIA)
The oxidation number of oxygen is almost always 2- in
a compound. There are exceptions.
a) Peroxides, O22- (each oxygen is 1-)
[Formed with elements in Groups IA and IIA]
b) Superoxides, O2- (each oxygen is ½-)
K, Rb and Ce are the only elements that form
Superoxides.
11
Sulfide, selenide, telluride, and polonide are always 22-, Se2-, Te2-, Po2-)
in binary salts. (S7/21/2015
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The Halogens (Group VIIA)
12
In metallic halides the halogen (F, Cl, Br, I,
At) always has an oxidation number equal to
1 -.
Remember: Never write the number 1.
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Oxidation States for Monatomic Ions
Atom
Oxidation State
Hydrogen (+) and (-)
Sodium
Barium
Aluminum
oxygen
13
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Oxidation State for Monatomic Ions
14
Atom
Oxidation State
Hydrogen (+) and (-)
H+, H-
Sodium
Na+
Barium
Ba2+
Aluminum
Al 3+
oxygen
O2-
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Balancing Using Oxidation Number
15
The oxidation number of any element in its
free state (uncombined with other elements)
is 0.
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Ionic Compounds
16
Ionic compounds consists of a metallic ion
and a non-metallic ion.
Positive ion is the cation
Negative ion is the anion.
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Chemical Formula indicates
17
The elements present
The relative number of atoms of each
element in the compound
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Binary Compounds
Binary compounds are made of two different
element.
-Combined chemically
-Definite proportion by mass
18
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Balancing Binary Compounds
Step I: Write the symbols for each ion
Example: Na Cl
Step II: Assign an oxidation number
Na+
Cl-
Step III: Balance the compound. The sum of
the oxidation numbers must be
zero. (Hint: Crisscross the charges. Don’t
include the signs.)
NaCl
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Al3+ S2-
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Al2S3
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Balancing Binary Compounds
What should you do if the charges are the
same?
Nothing. The formula is balanced. The
sum of the charges is “0”.
20
Example:
Ba 2+ O27/21/2015
= BaO
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Balancing Binary Formulas
21
Silver & chlorine
Zinc & oxygen
Calcium & bromine
Strontium & fluorine
Barium & chlorine
Calcium & chlorine
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Balancing Binary Formulas
22
Silver & chlorine
Zinc & oxygen
Calcium & bromine
Strontium & fluorine
Barium & chlorine
Calcium & chlorine
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AgCl
ZnO
CaBr2
SrF2
BaCl2
CaCl2
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Naming Binary Compounds
1. Write a balanced formula
2. Write the name of the 1st ion with no
changes.
3. Change the ending on the 2nd ion to –ide.
23
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Naming Binary Compounds
Example
NaCl = sodium chloride
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Naming Binary Compounds
25
Silver & chlorine
Zinc & oxygen
Calcium & bromine
Strontium & fluorine
Barium & chlorine
Calcium & chlorine
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Naming Binary Compounds
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Silver & chlorine
Zinc & oxygen
Calcium & bromine
Strontium & fluorine
Barium & chlorine
Calcium & chlorine
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silver chloride
zinc oxide
calcium bromide
strontium fluoride
barium chloride
calcium chloride
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Transitional Ions and Charges
27
Fe2+ Iron (II)
Fe3+ Iron (III)
Ni 2+
Ni 3+
Au+
Au 3+
Sn2+ Tin (II)
Sn4+ Tin (IV)
Zn 2+
Ag+1
Cu+1 Copper (I)
Cu+2 Copper (II)
Pb 2+
Pb 4+
Mn+2, +3, +4,+6,+7
Co +2
Co +3
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Naming Transitional Binary
Compounds
28
Fe2+ Iron (II)
Fe3+ Iron (III)
FeCl2 = iron (II) chloride
Sn2+ Tin (II)
Sn4+ Tin (IV)
SnCl2 = tin (II) chloride
Cu+1 Copper (I)
Cu+2 Copper (II)
CuCl = copper (I) chloride
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Polyatomic Ions
29
Polyatomic ions consist of two or more ions
that act as one in a chemical reaction.
Examples:
NO3nitrate
PO43- phosphate
SO42- sulfate
NO2- nitrite
SO32- sulfite
OH- hydroxide
ClO3- chlorate MnO4- permanganate
C2H3O2- acetate NH4+ ammonium
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Ternary Compounds
Ternary compounds are made up of three ions.
Two of the ions are joined together and act as
one. (polyatomic ion)
Example:
Na = sodium
30
NaNO3
N = nitrogen
O = oxygen
N & O make up the nitrate ion, NO37/21/2015
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Naming Ternary Compounds
1. Write a balanced formula
2. Write the name of the 1st ion. No changes to
name.
3. Write the name of the polyatomic ion.
31
NaNO3 = sodium nitrate
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Formula and Name of Ternary
Compounds
32
MgCO3
Pb(NO3)2
Ca(OH)2
Ba(NO3)2
Fe2(SO4)3
LiC2H3O2
KClO3
(NH4)2SO4
magnesium carbonate
lead nitrate
calcium hydroxide
barium nitrate
iron (III) sulfate
lithium acetate
potassium chlorate
ammonium sulfate
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Organic Compounds
Molecular compound
Made up of a small number of different
non-metal atoms
- Held together by forces known as
covalent bonds
The chemical formula gives you the number of
atoms of each element contained in a single
molecule of the compound
–
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Organic Compounds
Prefixes
Number
1
2
3
4
5
6
7
8
9
10
34
Prefix
monodi-/bi
tritetrapentahexaheptaoctanonadeca7/21/2015
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Organic Compounds
35
Carbon dioxide
CO2
Nitrogen trioxide NO3
Dinitrogen trioxide N2O3
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Nomenclature Review Wkst.
36
1. calcium chloride
2. magnesium oxide
2. MgCl2
3. iron (III) hydroxide
3. BaF2
4. potassium sulfate
4. KNO3
5. cesium nitrate
5. Al2S3
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1. NaCl
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Nomenclature Review
37
6. rubidium selenide
6. Li2O
7. strontium phosphate
7. SrSO4
8. potassium oxide
8. CuCl2
9. copper (I) oxide
9. (NH4)3PO4
10. ammonium sulfafte
10. BeBr2
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Nomenclature Review
38
11. sodium sulfide
11. H2SO4
12. rubidium sulfate
12. Mg3(PO4)2
13. calcium hydroxide
13. Na3PO4
14. sodium iodide
14. (NH4)2O
15. potassium hydroxide
15. AuCl3
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Nomenclature Review
39
16. lead (II) sulfide
16. Na2CO3
17. sodium carbonate
17. SiO2
18. iron (III) chloride
18. PbS
19. phosphoric acid
19. N2O3
20. barium sulfate
20. HNO3
21. silver nitrate
21. CaBr2
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Naming Ionic Compounds
40
1. sodium carbonate
129.0 g/mol
2. sodium hydroxide
40.00 g/mol
3. magnesium bromide
184.1 g/mol
4. potassium chloride
74.6 g/mol
5. iron (II) chloride
126.8 g/mol
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Naming Ionic Compounds
41
6. iron (III) chloride
162.3 g/mol
7. zinc hydroxide
99.4 g/mol
8. beryllium sulfate
114.1 g/mol
9. chromium (II) fluoride
90.0 g/mol
10. aluminum sulfide
150 g/mol
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Naming Ionic Compounds
42
11. lead (II) oxide
223.2 g/mol
12. lithium phosphate
115.7 g/mol
13. titanium (IV) iodide
556.3 g/mol
14. cobalt (II) nitride
204.7 g/mol
15. magnesium phosphide
134.9 g/mol
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Naming Ionic Compounds
43
16. gallium nitrite
207.7 g/mol
17. silver sulfite
296 g/mol
18. ammonium hydroxide
35.0 g/mol
19. aluminum cyanide
105.0 g/mol
20. beryllium acetate
127.0 g/mol
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Polyatomic Ions
44
Don’t separate the elements in the ion. Keep
them together.
Don’t: N + O3
But NO3-
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Determining the Charge on a
Polyatomic Ion
45
(NO3) -
( N5+ O36-)-
(SO4)2-
(S6+ O48-)2-
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Determine the oxidation number of the
ions in the polyatomic ions below
46
Phosphate
Chlorate
Sulfite
Permanganate
Nitrite
Hyroxide
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Oxidation States of Elements in
Polyatomic Ions
47
Phosphate
(P5+ O4 8-) 3-
Chlorate
(Cl5+ O36-) –
Sulfite
(S4+ O36- ) 2-
Hydroxide
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Oxidation States of Elements in
Polyatomic Ions
48
(Mn 7+ O42-) -
Permanganate
Nitrite
(N 5+ O24-) –
Acetate
(C26+H33-O24-) –
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What are the oxidation states of the
atoms below?
49
Sodium
Magnesium
Barium
Potassium
Aluminum
Calcium
chlorine
oxygen
sulfur
fluoride
bromine
iodine
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Oxidation States for Monatomic Ions
Atom
Oxidation State
Chlorine
Sulfur
Iodine
Lithium
Chromium (III)
50
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Oxidation States for Monatomic Ions
51
Atom
Oxidation State
Chlorine
Cl-
Sulfur
S2-
Iodine
I-
Lithium
Li+
Chromium (III)
Cr3+
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Oxidation States for Monatomic Ions
Iron (III)
Lead (II)
Copper (II)
52
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Oxidation States for Monatomic Ions
53
Iron (III)
Fe3+
Lead (II)
Pb2+
Copper (II)
Cu2+
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Metallic Elements With Variable
Oxidation Numbers
54
Transition metals, representative metals with
p and d sublevels, and the inner transition
metals typically have more than one
oxidation state in compounds..
Electrons are lost in the following order: p,s,d
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All Other Oxidation Numbers
55
Assigned so that the sum of the oxidation
numbers of each element equals the net
charge on the molecule or polyatomic ion.
In neutral compounds, the sum of the
positive and negative charge must equal 0.
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Polyatomic Elements
56
These elements exist as neutral molecules in nature.
Hydrogen, H2
Bromine, Br2
Nitrogen, N2
Iodine, I2
Oxygen, O2
Fluorine, F2
Chlorine, Cl2
Ozone, O3
Phosphorus, P4
Sulfur, S8
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Naming Binary Compounds
(Table in Packet)
57
Sodium & chlorine
Magnesium & oxygen
Lithium & fluorine
Iron & sulfur
Copper (II) & chlorine
Lead (II) & chlorine
Barium & oxygen
Calcium & hydrogen
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Naming Binary Compounds
(Table in Packet)
58
NaCl
MgO
LiF
FeS
CuCl2
PbCl2
AlCl3
BaO
CaH2
sodium chloride
magnesium oxide
lithium fluoride
iron (II) sulfide
copper (II) chloride
iron (II) chloride
aluminum chloride
barium oxide
calcium hydride
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Examples of Metallic Elements with
Variable Oxidation Numbers.
1st Ion
Formed
2nd Ion
Formed
3rd Ion
Formed
Vanadium
[Ar]4s23d3
V 2+
V 3+
V 4+ & V 5+
Iron
[Ar]4s23d6
Fe 2+
Fe 3+
Pb 2+
Pb 4+
Electron
Element
Lead
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Configuration
[Xe]
6s24f145d10
6p2
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Isoelectronic?
60
These elements are not isoelectronic with a
noble gas when the outermost electrons are
lost.
That is, they will not have the same number
of electrons as the noble gas before it them
in the periodic table.
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EXPERIMENT: WATER OF HYDRATION
61
Purpose:
Determine that all the water has been driven from a
hydrate by heating a sample to constant mass.
Use experimental data to calculate the moles of
water released by a hydrate
Infer the empirical formula of the hydrate from the
formula of the anhydrous compound and
experimental data.
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Common Oxidation Numbers for
Monatomic Ions
62
Na + = sodium
Mg2+ = magnesium
Ba2+ = barium
K + = potassium
Al3+ = aluminum
Sr2+ = strontium
Ca2+ = calcium
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Cl- = chloride
S2- = sulfide
O2- = oxygen
F- = fluoride
Br- = bromide
I= iodide
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Introduction
63
Many ionic compounds, when crystallized
from an aqueous solution, will take up
definite amounts of water as an integral part
of their crystal structure. This water of
crystallization may be driven off by heating
the hydrated substance to convert it to its
anhydrous form.
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SAFETY
64
Handle the crucible and cover with clean
crucible tongs only.
Heat objects can be hot enough to burn even
if they look cool.
Always use crucible tongs to handle
crucibles and covers.
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Procedures
65
1. Mass the crucible and cover. Record
2. Add the magnesium sulfate to the crucible.
3. Mass the crucible, cover and magnesium sulfate. Record
4. Place the crucible and cover on the triangle as
demonstrated.
5. Heat slowly for 3 min with the crucible partially covered.
6. Heat strongly for 10 min.
7. Remove crucible, cover and contents and let cool for 5
minutes.
8. Mass the crucible, cover and magnesium sulfate.
9. Heat strongly for 5 minutes.
10. Repeat #7 & 8.
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CLEANUP & DISPOSAL
66
Clean all apparatus and your lab station.
Return equipment to its proper place.
Dispose of the magnesium sulfate in the sink.
Flush with water.
Wash your hands thoroughly after all work is
finished and before you leave the lab.
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DATA TABLE
67
1. Mass of empty crucible and cover
2. Mass of crucible, cover and magnesium
sulfate hydrate
3. Mass of crucible, cover and anhydrous
magnesium sulfate after 1st heating
4. Mass of crucible, cover and anhydrous
magnesium sulfate after 2nd heating.
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Fundamentals of Chemistry
Homework: P. 114 – 115: 6 - 10
6. How many valence electrons are in an
atom of each of the following elements?
A)
B)
C)
D)
68
Ne = 8
Br = 7
S=6
Sr = 2
E)
F)
G)
H)
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Na = 1
As = 5
Sn = 4
In = 3
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FC : Question # 7
Classify each of the elements in question 6
as a metal, nonmetal, or metalloid.
A) Ne = nonmetal
B) Br = nonmetal
C) S = nonmetal
D) Sr = metal
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E)
F)
G)
H)
Na = metal
As = metalloid
Sn = metal
In = metal
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FC : Question # 8
Write the electron dot structure for each of
the following elements. What is the group
number of each element?
A) Cl = 7A or 17
E) Kr = 8A or 18
B) Mg = 2A
F) Cs = 1A
C) C = 4 A or 14
G) O = 6A or 16
D) Bi = 6A or 15
H) P = 5A or 15
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Lewis Structure
Lewis structure is just the symbol of the
element and the number of
electrons on the outermost energy level.
Example: sodium Na has one electron
On its outermost energy level. Thus
Na•
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FC : Question # 9
The electron dot structures of four elements
are shown. Without referring to the periodic
table, give the family name for each element.
A)
B)
C)
D)
72
iodine = halogen
barium = alkaline earth metal
rubidium = alkali metal
radon = noble gas
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FC : Question # 10
73
a) Find the synthetic elements on the
periodic table.
b) What are the atomic numbers?
c) Which synthetic elements are not found with
the others on the periodic table?
B) Elements that are 93 and higher are synthetic
elements.
C) Technetium (43) and promethium (61).
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FC: Hwk.: P. 115 ( 11 – 15)
List the elements along with their chemical
symbols and atomic numbers that have
names similar to the names of planets in the
solar system.
Mercury = Hg (80)
Uranium = U (92)
Neptunium = Np (93)
Plutonium = Pu7/21/2015
(94)
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12. Rb – Atomic mass (86.1 u)
K – density, 1.19 g/ml
Cs – melting point, 290 K
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13. Be and Sr
F and I
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14. Element
hydrogen
lithium
nitrogen
fluorine
cobalt
silver
iodine
mercury
(a) (b) (c)
1,1 nm g
2,1 m
s
2,15 nm g
2,17 nm g
4,9 m
s
5,11 m s
5,17 nm s
6,12 m l
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(d)
H(1 dot)
Li (1 dot)
N (5 dots)
F (7 dots)
I(7dots)
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15. Americium is radioactive.
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16. Electrical conductivity increases because
the outer level electrons are farther from the
nucleus and can move more freely
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Naming Ternary Compounds
Table in Packet
80
Iron (II) sulfite
Copper (II) nitrate)
Calcium permanganate
Silver nitrate
Potassium chlorate
Magnesium carbonate
Lead (II) hydroxide
Nickel (II) phosphate
Ammonium sulfite
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17. Bromine and mercury are liquids.
Mercury is a metal because it has two
valence electrons that are not tightly held.
Bromine is a nonmetal because it has seven
valence electrons that are tightly held.
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18. The noble gases are unreactive because
they have a filled valence level.
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19. As you move down a column, the atomic
number increases and the wavelength of the
mitted X ray decreases.
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21. Ni and Zn are corrosion resistant,
malleable, and relatively abundant.
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Question For Today
(Put in Cw/Hw Notebook)
Ionic or Molecular Compounds?
86
1.
2.
3.
4.
5.
6.
7.
sodium chloride NaCl
barium oxide BaO
carbon monoxide CO
carbon dioxide
CO2
calcium carbonate CaCO3
sulfur dioxide SO2
sodium nitrate NaNO3
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