polyatomic ions

NH₄⁺

ammonium

NH₂^–

amide

CN^–

cyanide

NCS^–

thiocyanate

C₂H₃O₂^–

acetate

OH^–

hydroxide

NO₂^–

nitrite

NO₃^–

nitrate

SO₃^–2

sulfite

SO₄^–2

sulfate

HSO₄^–

hydrogen sulfate (bisulfate)

S₂O₃^–2

thiosulfate

PO₃^–3

phosphite

PO₄^–3

phosphate

HPO₄^–2

hydrogen phosphate (biphosphate)

H₂PO₄^–

dihydrogen phosphate

MnO₄^–

permanganate

CO₃^–2

carbonate

HCO₃^–

hydrogen carbonate (bicarbonate)

ClO^–

hypochlorite

ClO₂^–

chlorite

ClO₃^–

chlorate

ClO₄^–

perchlorate

BrO^–

hypobromite

BrO₂^–

bromite

BrO₃^–

bromate

BrO₄^–

perbromate

IO^–

hypoiodite

IO₂^–

iodite

IO₃^–

iodate

IO₄^–

periodate

CrO₄^–2

chromate

Cr₂O₇^–2

dichromate

O₂^–2

peroxide

C₂O₄^–2

oxalate

BO₃^–3

borate