# How can I name ionic compounds with transition metals?

For example, we can make compounds of iron and chlorine which would be named iron chloride. Iron can have an oxidation number of +2 or +3 and hence we could make $F e C {l}_{2}$ or $F e C {l}_{3}$. To be able to tell these apart, we call the first one iron(II) chloride and the second one iron(III) chloride.