Table of Common Polyatomic Ions – Shaun M. Williams, PhD

Name	Formula	Name	Formula	Name	Formula
+1 Ions		-1 Ions (cont.)		-2 Ions
Ammonium	NH₄⁺	Perchlorate	ClO₄^–	Chromate	CrO₄^2-
Hydronium	H₃O⁺	Chlorate	ClO₃^–	Dichromate	Cr₂O₇^2-
-1 Ions		Chlorite	ClO₂^–	Peroxide	O₂^2-
Nitrate	NO₃^–	Hypochlorite	ClO^–	Sulfate	SO₄^2-
Nitrite	NO₂^–	Periodate	IO₄^–	Sulfite	SO₃^2-
Cyanide	CN^–	Iodate	IO₃^–	Hydrogen Phosphate	HPO₄^2-
Thiocyanate	SCN^–	Iodite	IO₂^–	Carbonate	CO₃^2-
Permanganate	MnO₄^–	Hypoiodite	IO^–	Oxalate	C₂O₄^2-
Hydroxide	OH^–	Perbromate	BrO₄^–	-3 Ions
Amide	NH₂^–	Bromate	BrO₃^–	Phosphate	PO₄^3-
Dihydrogen Phosphate	H₂PO₄^–	Bromite	BrO₂^–	Phosphite	PO₃^3-
Acetate	C₂H₃O₂^–	Hypobromite	BrO^–
Bicarbonate	HCO₃^–	Hydrogen Sulfate	HSO₄^–
Hydrogen Sulfide	HS^–	Hydrogen Sulfite	HSO₃^–