Common Polyatomic Ions (Alphabetical order by ion name)
NOTE: -ite ending means one less oxygen than the -ate form.
PREFIXES: per- = one more oxygen than -ate ; hypo- = one less oxygen than –ite
Ion Name
Ion
Symbol
Ion Name
Ion
Symbol
Ion Name
Ion
Symbol
Ion Name
Ion
Symbol
acetate
CH3CO21C2H3O21CH3COO1-
cyanate
OCN 1-
hydrogen
sulfite
HSO31-
perrhenate
ReO41-
amide
NH21-
cyanide
CN1-
hydroxide
OH1-
phosphate
PO43-
ammonium
NH41+
dichromate
Cr2O72-
hypobromite
BrO1-
phosphite
PO33-
arsenate
AsO43-
dihydrogen
phosphate
H2PO41-
hypochlorite
ClO1-
plumbate
PbO32-
arsenite
AsO33-
dihydrogen
phosphite
H2PO31-
hypoiodite
IO1-
plumbite
PbO22-
astatate
AtO31-
diphosphate
P2O74-
hypophosphite
H2PO21-
rhenate
ReO42-
azide
N31-
dithionate
S2O62-
iodite
IO21-
ruthenate
RuO42-
benzoate
C6H5COO1-
dithionite
S2O42-
iodate
IO31-
selenate
SeO42-
bicarbonate
HCO31-
ferricyanide
Fe(CN)63-
isocyanate
NCO1-
selenite
SeO32-
binoxalate
HC2O41-
ferrocyanide
Fe(CN)64-
manganate
MnO42-
silicate
SiO32-
bisulfate
HSO41-
formate
HCOO1-
molybdate
MoO42-
stannate
SnO32-
bisulfide
HS1-
fulminate
CNO 1-
monohydrogen
phosphate
HPO42-
stannite
SnO22-
bisulfite
HSO31-
hexachloroplatinate
PtCl62-
nitrate
NO31-
sulfate
SO42-
borate
BO32-
hexafluorosilicate
SiF62-
nitrite
NO21-
sulfite
SO32-
bromate
BrO31-
hydrazide
N2H31-
orthosilicate
SiO44-
superoxide
O21-
bromite
BrO21-
hydrogen
arsenate
HAsO42-
oxalate
C2O42-
tartrate
C4H4O62-
carbonate
CO32-
hydrogen
carbonate
HCO31-
ozonide
O31-
tellurate
TeO42-
chlorate
ClO31-
hydrogen
oxalate
HC2O41-
perbromate
BrO41-
tellurite
TeO32-
chlorite
ClO21-
hydrogen
phosphate
HPO42-
perchlorate
ClO41-
tetraborate
B4O72-
chromate
CrO42-
hydrogen
phosphite
HPO32-
periodate
IO41-
thiocyanate
SCN1-
chromite
CrO21-
hydrogen sulfate
HSO41-
permanganate
MnO41-
thiosulfate
S2O32-
citrate
C6H5O73-
hydrogen
sulfide
HS1-
peroxide
O22-
tungstate
WO42-
peroxydisulfate
S2O82-
vanadate
VO31-
Common Polyatomic Ions (Alphabetical order by formula)
NOTE: -ite ending means one less oxygen than the -ate form.
PREFIXES: per- = one more oxygen than -ate hypo- = one less oxygen than -ite
Ion
Symbol
Ion
Name
Ion
Symbol
Ion Name
Ion
Symbol
Ion Name
Ion
Symbol
Ion Name
AsO33-
arsenite
C4H4O62-
tatrate
IO41-
periodate
PtCl62-
hexachloroplatinate
AsO43-
arsenate
CrO21-
chromite
MnO42-
manganate
ReO42-
rhenate
chromate
MnO4
12-
AtO31-
astatate
CrO42-
BO32-
borate
Cr2O72-
dichromate
MoO4
B4O72-
tetraborate
Fe(CN)63-
ferricyanide
N31-
azide
SO32-
sulfite
BiO31-
bismuthate
Fe(CN)64-
ferrocyanide
NCO1-
isocyanate
SO42-
sulfate
BrO1-
hypobromite
HAsO42-
hydrogen
arsenate
NH21-
amide
S2O32-
thiosulfate
BrO21-
bromite
HCOO1-
formate
NH41+
ammonium
S2O42-
dithionite
BrO31-
bromate
HCO31-
hydrogen
carbonate or
bicarbonate
N2H31-
hydrazide
S2O62-
dithionate
BrO41-
perbromate
HC2O41-
hydrogen
oxalate or
binoxalate
NO21-
nitrite
S2O82-
peroxydisulfate
CH3CO21C2H3O21CH3COO1-
acetate
HPO32-
hydrogen
phosphite
NO31-
nitrate
SeO32-
selenite
benzoate
HPO42-
hydrogen
phosphate or
monohydrogen
phosphate
O21-
superoxide
SeO42-
selenate
C6H5O73-
citrate
H2PO21-
hypophosphite
O22-
peroxide
SiF62-
hexafluorosilicate
ClO1-
hypochlorite
H2PO31-
dihydrogen
phosphite
O31-
ozonide
SiO32-
silicate
ClO21-
chlorite
H2PO42-
dihydrogen
phosphate
OCN1-
cyanate
SiO44-
orthosilicate
ClO31-
chlorate
HS1-
hydrogen sulfide
or bisulfide
OH1-
hydroxide
SnO22-
stannite
ClO41-
perchlorate
HSO31-
hydrogen sulfite
or bisulfite
PO33-
phosphite
SnO32-
stannate
CN1-
cyanide
HSO41-
hydrogen sulfate
or bisulfate
PO43-
phosphate
TeO42-
tellurate
CNO1-
fulminate
IO1-
hypoiodite
P2O74-
diphosphate
TeO32-
tellurite
carbonate
IO21-
plumbite
VO31-
vanadate
oxalate
IO31-
plumbate
WO42-
tungstate
C6H5COO
CO32C2O42-
1-
iodite
iodate
PbO2
2-
PbO3
2-
permanganate
molybdate
2-
ruthenate
1-
thiocyanate
RuO4
SCN