Name ________ KEY _________________________________ Date _________ Period ______
Ionic vs. Molecular Compounds
1.
What holds the atoms together in an ionic bond?

2.
Compare and contrast a formula unit and a molecule.

3.
5.
Both represent the smallest ratio of atoms in a compound. A formula unit is the
smallest ratio of atoms in an ionic compound, and is not a single piece. A
molecule is 1 single covalently-bonded piece of a molecular compound.
Why don’t ionic compounds conduct electricity as solids? In what situations will they
conduct electricity?

4.
The attraction between oppositely-charged ions holds atoms together in an ionic
bond.
Ionic compounds do not conduct electricity when solid because the ions are held
in place. When dissolved in water, or melted to a liquid, ionic compounds will
conduct electricity.
Identify the following as being properties of ionic or molecular compounds.
a.
Ionic Compounds
High melting point
b.
Molecular Compounds
Involve only nonmetals
c.
Molecular Compounds
Insoluble in water if nonpolar
d.
Molecular Compounds
Low boiling point
e.
Ionic Compounds
Crystal lattice structure
f.
Molecular Compounds
Often gases or liquids at room temperature
g.
Ionic Compounds
Hard, rigid solids
h.
Ionic Compounds
Conduct electricity when molten
What type of bonds (ionic, covalent, both) are present in the following compounds?
a.
CaCl2
Ionic
e.
Fe2S3
Ionic
b.
CH4
Covalent
f.
P2O5
Covalent
c.
Na2CO3
Both
g.
NH4Br
Both
d.
PF3
Covalent
h.
KI
Ionic