Nomenclature of Inorganic Compounds - Chemistry LibreTexts
Aug 15, 2020· The transition metals may form more than one ion, thus it is needed to be specified which particular ion we are talking about. This is indied by assigning a Roman numeral after the metal. The Roman numeral denotes the charge and the oxidation state of the transition metal ion. For example, iron can form two common ions, Fe 2 + and Fe 3 +.