Polyatomic Ions

There are certain groups of atoms that act as though they were one single atom. They move as a unit in chemical reactions, very seldomly being broken apart. This group of atoms, called polyatomic ions, has a cumulative charge. We will be using these in naming compounds, balancing equations, moles, acids, and in several computer programs (not to mention test and exams).

acetate C₂H₃O₂ ^1-	citrate C₆H₅O₇ ^3-	peroxide O₂ ^2-
aluminate AlO₃ ^3-	cyanate OCN ^1-	phosphate PO₄ ^3-
amide NH₂ ^1-	cyanide CN ^1-	phosphite PO₃ ^3-
ammonium NH₄ ¹⁺	dichromate Cr₂O₇ ^2-	pyrophosphate P₄O₇ ^4-
arsenate AsO₄^3-	hydronium H₃O ¹⁺	selenate SeO₄ ^2-
arsenite AsO₃ ^3-	hydroxide OH ^1-	silicate SiO₃ ^2-
bicarbonate HCO₃ ^1-	hypochlorite ClO ^1-	sulfate SO₄ ^2-
borate BO₃ ^3-	iodate IO₃ ^1-	sulfite SO₃ ^2-
bromate BrO₃ ^1-	molybdate MoO₄ ^2-	tartrate C₄H₄O₆ ^2-
carbonate CO₃ ^2-	nitrate NO₃ ^1-	tellurate TeO₄ ^2-
chlorate ClO₃ ^1-	nitrite NO₂ ^1-	tetraborate B₄O₇ ^2-
chlorite ClO₂ ^1-	oxalate C₂O₄ ^2-	thiocyanate SCN ^1-
chromate CrO₄ ^2-	perchlorate ClO₄ ^1-	thiosulfate S₂O₃ ^2-
chromite CrO₂ ^1-	permanganate MnO₄ ^1-	tungstate WO₄ ^2-

Common Monatomic and Polyatomic Ions

1⁺		2⁺		3⁺		4⁺
Ammonium	NH₄	Barium	Ba	Aluminum	Al	Carbon (IV)	C
Cesium	Cs	Cadmium	Cd	Arsenic	As	Lead (IV)	Pb
Copper (I)	Cu	Calcium	Ca	Boron	B	Platinum (IV)	Pt
Gold (I)	Au	Carbon (II)	C	Chromium (III)	Cr	Polonium (IV)	Po
Hydrogen	H	Chromium(II)	Cr	Cobalt (III)	Co	Silicon	Si
Lithium	Li	Cobalt (II)	Co	Gallium	Ga	Tin (IV)	Sn
Mercury (I)	Hg	Copper (II)	Cu	Gold (III)	Au	Zirconium	Zr
Potassium	K	Iron (II)	Fe	Iron (III)	Fe
Rubidium	Rb	Lead (II)	Pb	Nickel (III)	Ni
Silver	Ag	Magnesium	Mg	Scandium	Sc
Sodium	Na	Mercury (II)	Hg
		Nickel (II)	Ni
		Platinum (II)	Pt
		Polonium (II)	Po
		Radium	Ra
		Strontium	Sr
		Tin (II)	Sn
		Zinc	Zn

1^-		2^-		3^-		4^-
Acetate	C₂H₃O₂	Carbonate	CO₃	Aluminate	AlO₃	Carbide	C
Bicarbonate	HCO₃	Chromate	CrO₄	Arsenate	AsO₄	Pyrophosphate	P₄O₇
Bromate	BrO₃	Dichromate	Cr₂O₇	Borate	BO₃
Bromide	Br	Molybdate	MoO₄	Citrate	C₆H₅O₇
Chlorate	ClO₃	Oxalate	C₂O₄	Nitride	N
Chlorite	ClO₂	Oxide	O	Phosphate	PO₄
Chloride	Cl	Selenate	SeO₄	Phosphide	P
Cyanide	CN	Selenide	Se	Phosphite	PO₃
Fluoride	F	Silicate	SiO₃
Hydroxide	OH	Sulfate	SO₄
Iodate	IO₃	Sulfide	S
Iodide	I	Sulfite	SO₃
Nitrate	NO₃	Tartrate	C₄H₄O₆
Nitrite	NO₂