Polyatomic ion

A polyatomic ion is an ion (chemical compound with an electrical charge) that is made of multiple atoms. A polyatomic ion can be either a cation (positive charge) or anion (negative charge).

Many minerals contain polyatomic anions. Polyatomic cations are rarer, and are usually made by people.

Some polyatomic ions

Cations			Anions
Charge	Formula	Name	Charge	Formula	Name
+1	H3O+	Hydronium	-1	OH−	Hydroxide
+1	NH+4	Ammonium	-1	NO−3	Nitrate
+2	Hg2+2	Mercury polycations	-1	CH3COO−	Acetate
+2	VO2+	Vanadyl ion	-2	SO2−4	Sulfate
			-2	CO2−3	Carbonate
			-3	C3H5O(COO)3−3	Citrate
			-3	PO3−4	Phosphate