Common Polyatomic Ions

Acetate

CH₃COO^-

Ammonium

NH₄⁺

Azide

N₃^-

Bromide

Br^-

Carbonate

CO₃^2-

Chlorate

ClO₃^-

Chloride

Cl^-

Chromate

CrO₄^2-

Cyanide

CN^-

Dichromate

Cr₂O₇^2-

Dihydrogen phosphate

H₂PO₄^-

Disulfide

S₂^2-

Fluoride

F^-

Hydride

H^-

Hydrogen carbonate or bicarbonate

HCO₃^-

Hydrogen phosphate

HPO₄^2-

Hydrogen sulfite or bisulfite

HSO₃^-

Hydroxide

OH^-

Nitrate

NO₃^-

Nitride

N^3-

Nitrite

NO₂^-

Oxide

O^2-

Perchlorate

ClO₄^-

Permanganate

MnO₄^-

Peroxide

O₂^2-

Phosphate

PO₄^3-

Sulfate

SO₄^2-

Sulfide

S^2-

Sulfite

SO₃^2-

Thiocyanate

SCN^-