Polyatomic Ions

NH4⁺

ammonium ion

Hg2 2+

mercury (I) ion

H3O+

Hydronium ion

CN-

Cyanide ion

O2 2-

Peroxide ion

CO3 2-

Carbonate ion

HCO3-

Hydrogen carbonate (or bicarbonate) ion

NO3-

Nitrate ion

NO2-

Nitrite ion

PO4 3-

Phosphate ion

HPO4 2-

Hydrogen phosphate (or biphosphate) ion

H2PO4-

dihydrogen phosphate ion

PO3 3-

Phosphite ion

SO4 2-

Sulfate ion

HSO4-

hydrogen sulfate (or bisulfate) ion

SO3 2-

Sulfite ion

HSO3-

hydrogen sulfite (or bisulfite) ion

OH-

hydroxide ion

ClO4-

perchlorate ion

ClO3-

chlorate ion

ClO2-

chlorite ion

ClO-

hypochlorite ion

BrO4-

perbromate ion

BrO3-

bromate ion

BrO2-

bromite ion

BrO-

hypobromite ion

IO4-

periodate ion

IO3-

Iodate ion

IO2-

Iodite ion

IO-

hypoiodite ion

OCN-

cyanate ion

SCN-

thiocyanate ion

CH3CO2-

acetate ion

C2O4 2-

oxalate ion

MnO4-

permanganate ion

CrO4 2-

chromate ion

Cr2O7 2-

dichromate ion