Common Polyatomic Ions

NH4+

ammonium

NO2-

nitrite

NO3-

nitrate

OH-

hydroxide

CN-

cyanide

MnO4-

permanganate

HCO3-

hydrogen carbonate

CIO2-

chlorite

CIO3-

chlorate

CIO4-

perchlorate

BrO3-

bromate

IO3-

iodate

IO4-

periodate

C2H3O2- (the numbers are bottom right of the elements)

acetate

H2PO4- (the numbers are bottom right of the elements)

dihydrogen phosphate

CO3 2- (the 2 is squared)

carbonate

SO3 2- (the 2 is squared)

sulfite

SO4 2- (the 2 is squared)

sulfate

S2 O3 2- (the 2 is squared)

thiosulfate

O2 2- (the 2 is squared)

peroxide

CrO4 2- (the 2 is squared)

chromate

Cr2 O7 2- (the 2 is squared)

dichromate

HPO4 2- (the 2 is squared)

hydrogen phosphate

PO4 3- (the 3 is squared)

phosphate

As O4 3- (the 3 is squared)

arsenate