Roman Numbers used in Chemical Formulae

For example, Copper has two valencies, 1 and 2 Many Transition Metal Elements (the block in the middle of the Periodic Table) can have more than one valency For example, Copper has two valencies, 1 and 2 The valency of such an element in a compound is written in brackets immediately after the name of the element. Do you know your roman numerals?

Examples… 1. Copper(I) oxide 1 2 Cu O Formula is Cu2O 2. Tin(IV) carbonate 2 1 4 2 Sn CO3 Formula is Sn(CO3)2

TRY… 1. Silver(I) sulphate Answer Ag2SO4 2. Lead(IV) oxide Answer PbO2 Answer Fe2S3 3. Iron(III) sulphide 4. Tin(II) phosphate Answer Sn3(PO4)2 Answer NiCl2 5. Nickel(II) chloride