I. Symbols and Charges for Monoatomic Ions

A. Fixed Charge

Symbol	Name	Symbol	Name
H⁺	hydrogen ion	H^-	hydride ion
Li⁺	lithium ion	F^-	fluoride ion
Na⁺	sodium ion	Cl^-	chloride ion
K⁺	potassium ion	Br^-	bromide ion
Ag⁺	silver ion	I^-	iodide ion
Mg²⁺	magnesium ion	O^2-	oxide ion
Ca²⁺	calcium ion	S^2-	sulfide ion
Ba²⁺	barium ion	N^3-	nitride ion
Zn²⁺	zinc ion	P^3-	phosphide ion
Al³⁺	aluminum ion
Bi³⁺	bismuth ion

B. Variable Charge

Symbol	Systematic Name	Common Name	Symbol	Systematic Name	Common Name

Cu⁺	copper(I) ion	cuprous ion	Hg₂²⁺	mercury(I) ion	mercurous ion
Cu²⁺	copper(II) ion	cupric ion	Hg²⁺	mercury(II) ion	mercuric ion
Fe²⁺	iron(II) ion	ferrous ion	Pb²⁺	lead(II) ion	plumbous ion
Fe³⁺	iron(III) ion	ferric ion	Pb⁴⁺	lead(IV) ion	plumbic ion
Sn²⁺	tin(II) ion	stannous ion	Co²⁺	cobalt(II) ion	cobaltous ion
Sn⁴⁺	tin(IV) ion	stannic ion	Co³⁺	cobalt(III) ion	cobaltic ion
Cr²⁺	chromium(II) ion	chromous ion	Ni²⁺	nickel(II) ion	nickelous ion
Cr³⁺	chromium(III) ion	chromic ion	Ni⁴⁺	nickel(IV) ion	nickelic ion
Mn²⁺	manganese(II) ion	manganous ion	Ti³⁺	titanium(III) ion	titanous ion
Mn³⁺	manganese(III) ion	manganic ion	Ti⁴⁺	titanium(IV) ion	titanic ion

II. Symbols and Charges for Polyatomic Ions

Formula	Name	Formula	Name

NO₃^-	nitrate ion	ClO₄^-	perchlorate ion
NO₂^-	nitrite ion	ClO₃^-	chlorate ion
CrO₄^2-	chromate ion	ClO₂^-	chlorite ion
Cr₂O₇^2-	dichromate ion	ClO^-	hypochlorite
CN^-	cyanide ion	MnO₄^-	permanganate ion
OH^-	hydroxide ion	O₂^2-	peroxide ion
CO₃^2-	carbonate ion	HCO₃^-	hydrogen carbonate ion (bicarbonate ion)
SO₄^2-	sulfate ion	HSO₄^-	hydrogen sulfate ion (bisulfate ion)
SO₃^2-	sulfite ion	HSO₃^-	hydrogen sulfite ion (bisulfite ion)
C₂O₄^2-	oxalate ion	HC₂O₄^-	hydrogen oxalate ion (binoxalate ion)
PO₄^3-	phosphate ion	HPO₄^2-	hydrogen phosphate ion
PO₃^3-	phosphite ion	H₂PO₄^-	dihydrogen phosphate ion
		HS^-	hydrogen sulfide ion (bisulfide ion)
C₂H₃O₂^-	acetate ion (an alternate way to write acetate is CH₃COO^-)

There is only one polyatomic cation, NH₄⁺ = ammonium ion