Common Polyatomic Ions

NH₄+

NH₄+

Ammonium

Hg₂+2

Dimercury (I)

C₂H₃O₂-

Acetate

HCO₃-

Bicarbonate

BrO₃-

Bromate

BrO₂-

Bromite

ClO₄-

Perchlorate

ClO₃-

Chlorate

ClO₂-

Chlorite

ClO-

Hypochlorite

CN-

Cyanide

SCN-

Thiocyanate

OH-

Hydroxide

NO₃-

Nitrate

NO₂-

Nitrite

MnO₄-

Permanganate

HSO₄-

Bisulfate

HSO₃-

Bisulfite

IO₃-

Iodate

IO₄-

Periodate

C₆H₅COO-

Benzoate

CO₃-2 (-2)

Carbonate

CrO₄-2 (-2)

Chromate

Cr₂O₇-2 (-2)

Dichromate

C₂O₄-2 (-2)

Oxalate

O₂-2 (-2)

Peroxide

SO₄-2 (-2)

Sulfate

SO₃-2 (-2)

Sulfite

S₂O₃-2 (-2)

Thiosulfate

SiO₃-2 (-2)

Silicate

MoO₄-2 (-2)

Molybdate

WO₄-2 (-2)

Tungstate

BO₃-3 (-3)

Borate

PO₄-3 (-3)

Phosphate

PO₃-3 (-3)

Phosphite

AsO₄-3 (-3)

Arsenate

AsO₃-3 (-3)

Arsenite

H₂PO₄-

Dihydrogen phosphate

HPO₄-2 (-2)

Hydrogen phosphate

Fe(CN)₆-3 (-3)

Hexacyannoferrate (III)

Fe(CN)₆-4 (-4)

Hexacyannoferrate (II)