Look at first nameIf it is ammonium, put NH4 in parentheses

and label it with a charge of +1If it is mercury I, put the Hg2 in parentheses

and label it with a charge of +2If it is a metal, write the symbol with charge

labeled. Note, if a roman numeral follows the metal name, that is the charge.

If it is a nonmetal, put its symbol. If there is a prefix, put the corresponding number as a subscript.

Look at second nameIf it is a nonmetal, write its symbol with its

charge labeled.If it is a polyatomic anion, put its formula in

parentheses and label it with its charge.If it is a nonmetal, put its symbol. If there is

a prefix, put the corresponding number as a subscript. Note, do not put a 1 as a subscript.

FinalizingIf your name is two nonmetals, you are

finished.If you have charges, crisscross them to get

subscripts. Make sure your subscripts go outside of

parenthesesMake sure you reduce the subscripts to their

lowest ratio

Hints• You only need to put parentheses around

polyatomic ions if there is to be a subscript outside them. However, it is not wrong to always put polyatomics in parentheses.– Na(OH) or NaOH– Ca(OH)2, but not CaOH2

• If the charges balance out, then no subscripts are necessary.– Na+1 NO3

-1 becomes simply NaNO3

– Mg+2 and O-2 becomes simply MgO

Examples • Sodium chloride Na+1 Cl -1 NaCl

• Sodium nitrate Na+1 (NO3) -1 NaNO3

• Sodium sulfate Na+1 (SO4) -2 Na2SO4

• Ammonium sulfate (NH4)+1 (SO4) -2 (NH4)2(SO4)

• Lead II iodide Pb+2 I -1 PbI2

• Lead II nitrate Pb+2 (NO3)-1 Pb(NO3)2

• Lead IV oxide Pb+4 O -2 Pb2O4 PbO2

• Dinitrogen pentoxide N2O5

• Aluminum oxide Al+3 O-2 Al2O3