Polyatomic

Acetate - C₂H₃O₂⁻ Ammonium - NH₄⁺ Arsenate - AsO₄³⁻ Arsenite - AsO₃³⁻ Bicarbonate (hydrogen carbonate) - HCO₃⁻ Carbonate - CO₃²⁻ Chlorate - ClO₃⁻ Chlorite - ClO₂⁻ Chromate - CrO₄²⁻ Cyanide - CN⁻ Dichromate - Cr₂O₇²⁻ Dihydrogen Phosphate - H₂PO₄⁻ Dihydrogen phosphite - H₂PO₃⁻ Hydrogen phosphate - HPO₄²⁻ Hydrogen phosphite - HPO₃²⁻ Hydronium - H₃O⁺ Hydroxide - OH⁻ Hypochlorite - ClO⁻ Nitrate - NO₃⁻ Nitrite - NO₂⁻ Oxalate - C₂O₄²⁻ Perchlorate - ClO₄⁻ Permanganate - MnO₄⁻ Peroxide - O₂²⁻ Phosphate - PO₄³⁻ Phosphite - PO₃³⁻ Sulfate - SO₄²⁻ Sulfite - SO₃²⁻ Thiocyanate - SCN⁻