Common Polyatomic Ions

Ordered according to charge and ion family * means you do not need to memorize them.

Ammonium

Ammonium

NH4(+)

Hydronium

H3O(+)

Mercury (I)

Hg2(2+)

Dihydrogen Phosphite

H2PO3(-)

Dihydrogen Phosphate

H2PO4(-)

Hydrogen Carbonate (Bicarbonate)

HCO3(-)

Hydrogen Sulfite

HSO3(-)

Hydrogen Sulfate

HSO4(-)

Nitrite

NO2(-)

Nitrate

NO3(-)

Hydroxide

OH(-)

Acetate**

CH3COO(-), CH2CO2(-), C2H3O2(-)

Chromite*

CrO2(-)

Cyanide

CN(-)

Cyanate

CNO(-)

Thiocyanate

CNS(-)

Superoxide*

O2(-)

Permanganate

MnO4(-)

Hypochlorite

ClO(-)

Chlorite

ClO2(-)

Chlorate

ClO3(-)

Perchlorate

ClO4(-)

Hypobromite

BrO(-)

Bromite

BrO2(-)

Bromate

BrO3(-)

Perbromate

BrO4(-)

Hypoiodite

IO(-)

Iodite

IO2(-)

Iodate

IO3(-)

Periodate

IO4(-)

Hydrogen Phosphite

HPO3(2-)

Hydrogen Phosphate

HPO4(2-)

Carbonate

CO3(2-)

Sulfite

SO3(2-)

Sulfate

SO4(2-)

Thiosulfate

S2O3(2-)

Silicate

SiO3(2-)

Carbide*

C2(2-)

Oxalate

C2O4(2-)

Chromate

CrO4(2-)

Dichromate

Cr2O7(2-)

Tartrate

C4H4O6(2-)

Molybdate

MoO4(2-)

Peroxide

O2(2-)

Disulfide*

S2(2-)

Phosphite

PO3(3-)

Phosphate

PO4(3-)

Arsenite

AsO3(3-)

Arsenate

AsO4(3-)