Common Polyatomic Ions

NH4+

Ammonium Ion
Cation

C2H3O2-

Acetate Ion
Anion

CO32-

Carbonate Ion
Anion

ClO3-

Chlorate Ion
Anion

ClO2-

Chlorite Ion
Anion

CrO42-

Chromate Ion
Anion

CN-

Cyanide Ion
Anion
(Note the suffix -ide is an exception to the general -ate and -ite rule.)

Cr2O72-

dichromate Ion
Anion

HCO3-

hydrogen carbonate ion
Anion

HSO4-

hydrogen sulfate ion
Anion

OH-

hydroxide Ion
Anion
(Note that the suffix -ide is an exception to the general -ate and -ite rule

ClO-

hypochlorite ion
Anion

NO3-

nitrate ion
Anion

NO2-

nitrite ion
Anion

ClO4-

Perchlorate Ion
Anion

MnO4-

permanganate ion
Anion

PO43-

phosphate Ion
Anion

SO42-

sulfate ion
Anion

SO32-

sulfite ion
Anion