polyatomic ions

ammonium

NH₄⁺

azide

N₃^-

cyanide

CN^-

hydroxide

OH^-

acetate

C₂H₃0₂^-

bicarbonate or hydrogen carbonate

HCO₃^-

bisulfate or hydrogen sulfate

HSO₄^-

bisulfite or hydrogen sulfite

HSO₃^-

dihydrogen phosphate

H₂PO₄^-

nitrate

NO₃^-

nitrite

NO₂^-

permanganate

MnO₄^-

thiocyanate

SCN^-

hypochlorite

ClO^-

chlorite

ClO₂^-

chlorate

ClO₃^-

perchlorate

ClO₄^-

hypobromite

BrO^-

bromite

BrO₂^-

bromate

BrO₃^-

perbromate

BrO₄^-

hypoiodite

IO^-

iodite

IO₂^-

iodate

IO₃^-

periodate

IO₄^-

carbonate

CO₃^2-

chromate

CrO₄^2-

dichromate

Cr₂O₇^2-

biphosphate or hydrogen phosphate

HPO₄^2-

oxalate

C₂O₄^2-

peroxide

O₂^2-

silicate

SiO₃^2-

selenate

SeO₄^2-

selenite

SeO₃^2-

sulfate

SO₄^2-

sulfite

SO₃^2-

arsenate

AsO₄^3-

arsenite

AsO₃^3-

phosphate

PO₄^3-

phosphite

PO₃^3-