This document provides information on naming and writing formulas for ionic compounds: - Ions are atoms or groups of atoms that have gained or lost electrons, giving them a positive or negative charge. Common ions and their charges should be memorized. - Prefixes indicate the number of atoms in polyatomic ions or in compound names. - To name ionic compounds, the cation (positively charged ion) is named first followed by the anion (negatively charged ion). Transition metals use Stock notation to indicate charge. - To write formulas, the charges of ions are used to balance the total charge of the compound to be neutral, choosing ions that satisfy the smallest whole number ratio.

2. Atoms/ groups of atoms with an electrical
charge
 Positive Ions
 Loses
electrons
 Negative Ions
 Gains
electrons
MEMORIZE the names and charges
of common ions – p 19

3. Prefix Meaning
Mono-
Di-
Tri-
Tetra-
Penta-
One
Two
Three
Four
Five

4.  Metal and Non-metal:
Metal + Non-metal + “-ide”
 Non-metal and Non-metal:
• Name first non-metal, then
second non-metal and add “–ide”
• Use prefixes for ratio’s of
elements
Elements to the left of periodic table
are named FIRST!!!

5.  Name cation first, then anion
 If the cation is a transition metal:
• Ion has more than one possible
charge
• Use Stock-notation to indicate
charge (Roman numerals after
name)

6. Name the following compounds:
a) CaBr2
b) N2S5
c) V2O5 (V5+)
d) ZnSO4
e) (NH4)3PO4
f) Na3P

7. Na2CO3
Two Sodium
Ions
Sodium
Carbon
Oxygen
Three Oxygen
Atoms

8.  Group I = +1
 Group II = +2
 Group III = +3
 Group IV = + 4
 Group V = -3
 Group VI = -2
 Group VII = -1
 Group VIII = Do Not
form BONDS!!!

9.  Transitionmetals
• Indicated by Stock-notation
• Know general charges – p19
 Poly-atomic ions
• Know charges – p 19

10.  Substances combine in such a way that the
compound is neutral
• Sum of charges = 0
 Choose ion with largest charge
• Assume there are only one atom of that
ion in the compound
 Set number of atoms of other ion = x
• Solve for x
 Remove fractions to obtain whole numbers

11. Write chemical formulae for compounds of the
following substances:
a) Sodium and oxygen
b) Potassium sulphide
c) Iron(II)chloride
d) Magnesium carbonate
e) Calcium Nitrate
f) Aluminium oxide
g) Ammonium sulphate