Symbols and Charges for Monoatomic Ions

Symbols and Charges for Monoatomic Ions

Fixed Charge

Symbol         Name                   Symbol         Name

H⁺              hydrogen ion           H^-              hydride

Li⁺             lithium ion            F^-              fluoride

Na⁺             sodium ion             Cl^-             chloride

K⁺              potassium ion          Br^-             bromide

Rb⁺             rubidium ion           I^-              iodide

Cs⁺             cesium ion             O^2-             oxide

Be²⁺            beryllium ion          S^2-             sulfide

Mg²⁺            magnesium ion          Se^2-            selenide

Ca²⁺            calcium ion            Te^2-            telluride

Sr²⁺            strontium ion          N^3-             nitride

Ba²⁺            barium ion             P^3-             phosphide

Ra²⁺            radium ion             As^3-            arsenide

Ag⁺             silver ion

Zn²⁺            zinc ion               Al³⁺            aluminum ion

Note that the letters in an ion's name before the -ide ending is the stem.

For example, the stem for bromide is brom-. Also, just in case, the P for

phosphide is a capital P.

Symbols and Charges for Monoatomic Ions

Variable Charge

        Systematic name Common                 Systematic name Common

Symbol  (Stock system) name           Symbol  (Stock system) name

Cu⁺     copper(I)      cuprous        Hg₂²⁺    mercury(I)     mercurous

Cu²⁺    copper(II)     cupric         Hg²⁺    mercury(II)    mercuric

Fe²⁺    iron(II)       ferrous        Pb²⁺    lead(II)       plumbous

Fe³⁺    iron(III)      ferric         Pb⁴⁺    lead(IV)       plumbic

Sn²⁺    tin(II)        stannous       Co²⁺    cobalt(II)     cobaltous

Sn⁴⁺    tin(IV)        stannic        Co³⁺    cobalt(III)    cobaltic

Cr²⁺    chromium(II)   chromous       Ni²⁺    nickel(II)     nickelous

Cr³⁺    chromium(III)  chromic        Ni⁴⁺    nickel(IV)     nickelic

Mn²⁺    manganese(II)  manganous      Au⁺     gold(I)        aurous

Mn³⁺    manganese(III) manganic       Au³⁺    gold(III)      auric

Symbols and Charges for Polyatomic Ions

Formula        Name                   Formula        Name

NO₃^-            nitrate                ClO₄^-           perchlorate

NO₂^-            nitrite                ClO₃^-           chlorate

CrO₄^2-          chromate               ClO₂^-           chlorite

Cr₂O₇^2-          dichromate             ClO^-            hypochlorite

CN^-             cyanide                IO₄^-            periodate

MnO₄^-           permanganate           IO₃^-            iodate

OH^-             hydroxide              IO^-             hypoiodite

O₂^2-            peroxide               BrO₃^-           bromate

NH₂^-            amide                  BrO^-            hypobromite

CO₃^2-           carbonate              HCO₃^-           hydrogen carbonate (bicarbonate)

SO₄^2-           sulfate                HSO₄^-           hydrogen sulfate (bisulfate)

SO₃^2-           sulfite                HSO₃^-           hydrogen sulfite (bisulfite)

C₂O₄^2-           oxalate                HC₂O₄^-          hydrogen oxalate (binoxalate)

PO₄^3-           phosphate              HPO₄^2-          hydrogen phosphate

PO₃^3-           phosphite              H₂PO₄^-          dihydrogen phosphate

S₂O₃^2-           thiosulfate            HS^-             hydrogen sulfide

AsO₄^3-          arsenate               BO₃^3-           borate

SeO₄^2-          selenate               B₄O₇^2-           tetraborate

SiO₃^2-          silicate               SiF₆^2-          hexafluorosilicate

C₄H₄O₆^2-  tartrate

C₂H₃O₂^-          acetate  (an alternate way to write acetate is CH₃COO^-)

There is one positive polyatomic ion. It is NH₄⁺ and is called the ammonium ion.

Note: Writing just the plus sign or minus sign for ions with +1 or -1 charges is

acceptable.