Common Polyatomic Ions

carbonate

CO3 2-

bicarbonate

HCO3 1-

phosphate

PO4 3-

hydroxide

OH 1-

peroxide

O2 2-

cyanide

CN 1-

sulfate

SO4 2-

sulfite

SO3 2-

nitrate

NO3 1-

nitrite

NO2 1-

ammonium

NH 4+

acetate

CH3COO 1-