Oxidation number

The oxidation number of a central atom in a coordination compound is the charge that it would have if all the ligands were removed along with the electron pairs that were shared with the central atom.^[1] It is used in the nomenclature of inorganic compounds. It is represented by a Roman numeral; the plus sign is omitted for positive oxidation numbers. The oxidation number is placed either as a right superscript to the element symbol, e.g. Fe^III, or in parentheses after the name of the element, e.g. iron(III): in the latter case, there is no space between the element name and the oxidation number.