Polyatomic Ion

Group of atoms that have a charge (positive or negative)

NH₄⁺

Ammonium

OH^-

Hydroxide

CN^-

Cyanide

CH₃CO₂^-

Acetate

SO₃^2-

Sulfite

SO₄^2-

Sulfate

HSO₄^-

Hydrogen sulfate (bisulfate)

S₂O₃^2-

Thiosulfate

PO₄^3-

Phosphate

HPO₄^2-

Hydrogen phosphate

H₂PO₄^-

Dihydrogen phosphate

SCN^-

Thiocyanate

OCN^-

Cyanate

NO₂^-

Nitrite

NO₃^-

Nitrate

ClO^-

Hypochlorite

ClO₂^-

Chlorite

ClO₃^-

Chlorate

ClO₄^-

Perchlorate

CO₃^2-

Carbonate

HCO₃^-

Hydrogen carbonate (bicarbonate)

C₂O₄^2-

Oxalate

Cr₂O₇^2-

Dichromate

CrO₄^2-

Chromate

MnO₄^-

Permanganate

CH₄

Methane

IO₂^-

Iodite