Physical Science
Chapter 5 Review Packet
Name: __________________
Period: ______ Date: _____
1)
Why do atoms form compounds?
-Atoms form compounds to become more stable.
2)
How many electrons do most atoms want in their outer energy level in order to be chemically
stable?
-Most atoms want 8 valence electrons to be stable. A few only want 2.
3)
Why are noble gases relatively nonreactive?
-They already have all the valence electrons they need to be stable.
4)
What are polyatomic ions?
-An ion that is made of more than 1 type of atom.
5)
How many atoms of each element are present in one molecule of Mg(NO3)2?
Mg – 1 atom, N – 2 atoms, O – 6 atoms
6)
What is the oxidation # for Barium?
-oxidation # is the # of electrons an atom will gain, lose, or share to be stable. Barium’s is +2
(give 2 electrons)
7)
Name 3 properties of most ionic compounds?
- High melting points, crystal structure, conduct electricity when dissolved in water, and formed
between metals and nonmetals.
8)
Name 3 properties of most covalent compounds?
-Low melting points, do not conduct electricity when dissolved in water, and formed between
nonmetals
9)
Which of the following elements would Lithium most likely react with and why? K, Mg, Cl, Na
-Cl because Cl is the only element in the list that wants to take an electron. Lithium and all the
other elements in the list want to give electrons.
10)
How do you tell the difference between polar and non-polar molecules?
-Nonpolar bonds will have either identical atoms, or will have symmetry to balance out
differences in how they pull.
11)
Name the following covalent molecules and indicate if they are polar or nonpolar.
polar - water (dihydrogen monoxide)
nonpolar – dicarbon tetrahydride
12)
Complete the following chart.
Element Symbol
Ca
N
A) Dot Diagram
Ca with 2 dots around it
N with 5 dots around
Give 2
Take 3
Ca+2
N-3
B) How many electrons
transferred?
C) Ion symbol
D) Chemical formula for
compound
E) Name of compound
Ca3N2
Calcium nitride
13)
a. 13 protons, 14 neutrons, 13 electrons
b. center has 13+ and 14n, 1st ring has 2 electrons, 2nd ring has 8
electrons, 3rd ring has 3 electrons.
c. 3 dots in dot diagram
14)
Name the following compounds:
Ionic Compounds
a. Li4C
lithium carbide
€
15)
Covalent Molecules
d. P2S3
diphosphorus
trisulfide
b. Mg3N2
Magnesium nitride
e. CF4
Carbon tetrafluoride
c. Mg(PO 4 ) 2
magnesium phosphate
f. N2O5
Dinitrogen pentaoxide
Polyatomic Ions
Name
Formula
Ammonium NH +1
4
−1
Acetate
C 2H 3O 2
−1
Chlorate
ClO 3
−1
Hydroxide
OH
−1
Nitrate
NO 3
Carbonate
CO −2
3
Sulfate
SO −2
4
Phosphate
PO −3
4
Are the following ionic or covalent compounds? How can you tell?
a. BaCl2
b. CO
Ionic – Barium is a metal
covalent – all nonmetals
16)
Identify if the following compounds are ionic or covalent
AND write their chemical names.
c. KCl
a. KNO3
ionic – potassium chloride
Ionic – potassium nitrate
b. S4N2
covalent – tetrasulfur dinitride
17)
d. NH4OH
ionic (NH4+1 is a polyatomic ion)
– ammonium hydroxide
Identify if the following compounds are ionic or covalent AND write their chemical formulas.
a. sodium nitride
e. carbon dioxide
ionic – Na is a metal
covalent – all nonmetals or has prefixes
Na3N
CO2
b. beryllium chloride
ionic – Be is a metal
BeCl2
f. calcium phosphate
ionic – calcium is metal
Ca3(PO4)2
c. triphosphorus pentachloride
covalent – all nonmetals or has prefixes
P3Cl5
g. tetraphosporus heptasulfide
covalent – all nonmetals or has prefixes
P4 S7
d. potassium carbonate
ionic – potassium is a metal
KCO3