Common Ions +2 -2

Sr +2
Strontium ion

O2 -2

Peroxide
Co +2
Cobalt (II) ion
SeO4 -2
Selenate
Cu +2
Copper (II) ion

C2O4 -2

Oxalate
Fe +2
Iron (II) ion
SiF6 -2
Hexafluorosilicate

Zn +2

Zinc ion

C4H4O6 -2

Tartrate
Ca +2
Calcium ion
CO3 -2
Carbonate

Hg2 +2

Mercury (II) ion
SO4 -2
Sulfate
Pb +2
Lead (II) ion
SO3 -2
Sulfite

Cd +2

Cadmium ion
CrO4 -2
Chromate
Mn +2
Manganese (II) ion
Cr2O7 -2

Dichromate

Ni +2
Nickel (II) ion
S -2
Sulfide
Ba +2
Barium ion
O -2
Oxide
Sn +2

Tin (II) ion

SiO3 -2
Silicate
Se -2
Selenide