1. Formulas for Binary Ionic Compounds
Metal Ion (+) cation same name
Nonmetal ion (-) anion ends -ide
Total (+) charge must equal total (-) charge
(i.e. the sum of the charges must = 0)
Transition Metal Ions
Many have more than one positive ion charge
Use Roman numerals to indicate which charge

2. Writing Balanced Formulas
Write the (+) cation first, then the (-) anion
Use “subscripts” to indicate multiples of an ion
Final balanced formula has no ion charges.
Naming Binary Ionic Compounds
Metal name is unchanged
(use Roman numerals if multivalent)
Nonmetal ends in - “ide”

3. Practice K and F Ca and Br Mg and N Na and S Ba and O
 Write formulas for compounds containing the
following elements:
K and F
Ca and Br
Mg and N
Na and S
Ba and O

4. Practice K and F Ca and Br Mg and N Na and S Ba and O K+ F- KF Ca2+
 Write formulas for compounds containing the
following elements:
K and F
Ca and Br
Mg and N
Na and S
Ba and O K+ F- KF
Ca2+
Br-
CaBr2
Mg2+
N3-
Mg3N2
Na+
S2-
Na2S
Ba2+
O2-
BaO

5. Practice following elements: K and F Ca and Br Mg and N Na and S
 Write names for compounds containing the
following elements:
K and F
Ca and Br
Mg and N
Na and S
Ba and O KF
potassium fluoride
CaBr2
calcium bromide
Mg3N2
magnesium nitride
Na2S
sodium sulfide
BaO
barium oxide

6. Write formulas for these compounds: strontium chloride
Practice
 Write formulas for these compounds:
strontium chloride
potassium iodide
aluminum nitride
calcium sulfide
sodium oxide

7. Write formulas for these compounds: strontium chloride
Practice
 Write formulas for these compounds:
strontium chloride
potassium iodide
aluminum nitride
calcium sulfide
sodium oxide
Sr2+
Cl-
SrCl2 K+ I- KI
AlN
Al3+
N3-
Ca2+
S2-
CaS
Na+
O2-
Na2O

8. Binary Ionic Compounds Containing a Metal
that can form Two or More Types of Cations:
Name these compounds using the “stock system”:
1. Write the name of the cation
2. Write the charge of the cation as a Roman
numeral in parentheses.
3. Write the stem of the anion with the suffix
–ide

9. Practice
Write the name for each of the following
compounds using the stock system:
PbI2
SnF4
Fe2O3
CuO

10. Write the name for each of the following
Practice
Write the name for each of the following
compounds using the stock system:
PbI2
SnF4
Fe2O3
CuO 2+ 1-
lead (II) iodide 4+ 1-
tin (IV) fluoride 3+ 2-
iron (III) oxide 2+ 2-
copper (II) oxide