Polyatomic ions

acetate

C2H3O2 (CH3COOH) -1

bicarbonate (hydrogen carbonate)

HCO3 -1

bisulfate

HSO4 -1

bisulfite

HSO3 -1

bromate

BrO3 -1

bromite

BrO2 -1

chlorate

ClO3 -1

chlorite

ClO2 -1

cyanide

CN -1

dihydrogen phosphate

H2PO4 -1

hydroxide

OH -1

hypobromite

BrO -1

hypochlorite

ClO -1

nitrate

NO3 -1

nitrite

NO2 -1

perchlorate

ClO4 -1

permanganate

MnO4 -1

thiocyanate

SCN -1

carbonate

CO3 -2

chromate

CrO4 -2

dichromate

Cr2O7 -2

hydrogen phosphate

HPO4 -2

manganate

MnO4 -2

oxalate

C2O4 -2

sulfate

SO4 -2

sulfite

SO3 -2

thiosulfate

S2O3 -2

phosphate

PO4 -3

phosphite

PO3 -3

ammonium

NH4 +1

hydronium

H3O +1

mercury(I)

Hg2 +2