Common Polyatomic Ions

ammonium

NH₄¹⁺

nitrate

NO₃^1-

nitrite

NO₂^1-

bicarbonate

HCO₃^1-

bisulfate

HSO₄^1-

bisulfite

HSO₃^1-

permanganate

MnO₄^1-

hypochlorite

ClO^1-

chlorite

ClO₂^1-

chlorate

ClO₃^1-

perchlorate

ClO₄^1-

acetate

C₂H₃O₂^1-

hydroxide

OH^1-

cyanide

CN^1-

thiocyanate

SCN^1-

formate

HCOO^1-

sulfite

SO₃^2-

sulfate

SO₄^2-

oxalate

C₂O₄^2-

chromate

CrO₄^2-

dichromate

Cr₂O₇^2-

peroxide

O₂^2-

carbonate

CO₃^2-

thiosulfate

S₂O₃^2-

thiosulfite

S₂O₂^2-

phosphate

PO₄^3-

phosphite

PO₃^3-