common polyatomic ions

C2H3O2-

acetate

NH4+

ammonium

CO3 2-

carbonate

ClO3-

chlorate

ClO2-

chlorite

CrO4 2-

chromate

CN-

cyanide

Cr2O7 2-

dichromate

HCO3-

bicarbonate

HSO4-

bisulfate

HSO3-

bisulfite

OH-

hydroxide

ClO-

hypochlorite

NO3-

nitrate

NO2-

nitrite

C2O4 2-

oxalate

ClO4-

perchlorate

MnO4-

permanganate

PO4 3-

phosphate

SO4 2-

sulfate

SO3 2-

sulfite