Common polyatomic ions

NH₄⁺

ammonium

CH₃CO₂^-

acetate

CN^-

cyanide

ClO^-

hypochlorite

ClO₂^-

chlorite

ClO₃^-

chlorate

ClO₄^-

perchlorate

H₂PO₄^-

dihydrogen phosphate

HCO₃^-

hydrogen carbonate (bicarbonate)

HSO₄^-

hydrogen sulfate (bisulfate)

OH^-

hydroxide

MnO₄^-

permanganate

NO₂^-

nitrite

NO₃^-

nitrate

CO₃^2-

carbonate

CrO₄^2-

chromate

Cr₂O₇^2-

dichromate

O₂^2-

peroxide

HPO₄^2-

hydrogen phosphate

SO₃^2-

sulfite

SO₄^2-

sulfate

S₂O₃^2-

thiosulfate

PO₄^3-

phosphate