Flexi Says: Most transition metals differ from the metals of Groups 1, 2, and 13 in that they are capable of forming more than one cation with different ionic charges. As an example, iron commonly forms two different ions. It can sometimes lose two electrons to form the Fe2+ ion, while at other times it loses three electrons to form the Fe3+ ion. Tin and lead, though members of the p block rather than the d block, also are capable of forming multiple ions.
