Writing Formulas

Phosphorus pentachloride

Identify subscript with pretext P1Cl5

Remove 1s PCl5

Binary(Acids H+_)

Hydrosulfuric Acid

Hydro becomes H remove "ic" to get Sulfer (S)

Find the oxidation number H+1S+2

Criss cross H2S1

Reduce H2S

Ternary(H+polyatomic Ion)

Chloric Acid

Change "ic" to "ate"

Find the symbol Chlorate, attach the hydrogen symbol to the front of the polyatomic compud

HClO3

Identify Element Mg(ClO3)-1

Identify polyatomic or nonmetal (ClO3)-1

Find oxidation number Mg+2(ClO3)-1

Criss Cross numbers of oxidation to make subscripts

Reduce to eliminate the 1s

Check the Prefix and Suffix for the hydrocarbons Methane

the suffix "ane" has the formula Cn H2n +2

add the prefix to the end of H

C1 H2(1) +2

solve and reduce

C1 H4