Polyatomic Ion

Polyatomic ions are charged molecules. The atoms within a polyatomic ion are usually very tightly bound together, the ion retains its identity within ionic compounds and over the course of many chemical reactions.

List of Polyatomic Ions

Polyatomic Ion Charge = +1
ammonium – NH₄⁺

Polyatomic Ion Charge = -1
acetate – C₂H₃O₂^-
bicarbonate (or hydrogen carbonate) – HCO₃^-
bisulfate (or hydrogen sulfate) – HSO₄^-
chlorate – ClO₃^-
chlorite – ClO₂^-
cyanate – OCN^-
cyanide – CN^-
dihydrogen phosphate – H₂PO₄^-
hydroxide – OH^-
nitrate – NO₃^-
nitrite – NO₂^-
perchlorate – ClO₄^-
permanganate – MnO₄^-
thiocyanate – SCN^-

Polyatomic Ion Charge = -2
carbonate – CO₃^2-
chromate – CrO₄^2-
dichromate – Cr₂O₇^2-
hydrogen phosphate – HPO₄^2-
peroxide – O₂^2-
sulfate – SO₄^2-
sulfite – SO₃^2-
thiosulfate – S₂O₃^2-

Polyatomic Ion Charge = -3
borate – BO₃^3-
phosphate – PO₄^3-