Polyatomic ions are ions that contain more than one element. This polyatomic ions list contains many common ions, grouped by charge. Each entry contains the ion’s name, molecular formula and chemical structure.
+1 Polyatomic Ions
| Ion | Formula | Structure |
| Ammonium | NH4+ |  |
| Hydronium | H3O+ |  |
-1 Polyatomic Ions
| Ion | Formula | Structure |
| Acetate | C2H3O2– |  |
| Bicarbonate | HCO3– |  |
| Bisulfate | HSO4– |  |
| Chlorate | CO3– |  |
| Chlorite | ClO2– |  |
| Cyanate | OCN– |  |
| Cyanide | CN– |  |
| Dihydrogen phosphate | H2PO4– |  |
| Dihydrogen phosphite | H2PO3– |  |
| Hydroxide | OH– |  |
| Nitrate | NO3– |  |
| Nitrite | NO2– |  |
| Perchlorate | ClO4– |  |
| Permanganate | MnO4– |  |
| Thiocyanate | SCN– |  |
-2 Polyatomic Ions
| Ion | Formula | Structure |
| Carbonate | CO32- |  |
| Chromate | CrO42- |  |
| Dichromate | Cr2O72- |  |
| Hydrogen phosphate | HPO42- |  |
| Peroxide | O22- |  |
| Silicate | SiO32- |  |
| Sulfate | SO42- |  |
| Sulfite | SO32- |  |
| Thiosulfate | S2O32- |  |
-3 Polyatomic Ions
| Ion | Formula | Structure |
| Phosphate | PO43- |  |
| Phosphite | PO33- |  |