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 O2- oxide Be2+ beryllium ion S2- sulfide Mg2+ magnesium ion Se2- selenide Ca2+ calcium ion Te2- telluride Sr2+ strontium ion N3- nitride Ba2+ barium ion P3- phosphide Ra2+ radium ion As3- arsenide Ag+ silver ion Ni2+ nickel 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-. The P for phosphide is a capital P. Some sources will have nickel as a variable charge monoatomic ion, the charges being +2 and +4.
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 Au+ gold(I) aurous Cr3+ chromium(III) chromic Au3+ gold(III) auric Mn2+ manganese(II) manganous Mn3+ manganese(III) manganic
Symbols and Charges for Polyatomic Ions
Formula Name Formula Name NO3- nitrate ClO4- perchlorate NO2- nitrite ClO3- chlorate CrO42- chromate ClO2- chlorite Cr2O72- dichromate ClO- hypochlorite CN- cyanide IO4- periodate MnO4- permanganate IO3- iodate OH- hydroxide IO- hypoiodite O22- peroxide BrO3- bromate NH2- amide BrO- hypobromite CO32- carbonate HCO3- hydrogen carbonate (bicarbonate) SO42- sulfate HSO4- hydrogen sulfate (bisulfate) SO32- sulfite HSO3- hydrogen sulfite (bisulfite) C2O42- oxalate HC2O4- hydrogen oxalate (binoxalate) PO43- phosphate HPO42- hydrogen phosphate PO33- phosphite H2PO4- dihydrogen phosphate S2O32- thiosulfate HS- hydrogen sulfide AsO43- arsenate BO33- borate SeO42- selenate B4O72- tetraborate SiO32- silicate SiF62- hexafluorosilicate C4H4O62- tartrate SCN- thiocyanate 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.