Why is Fe2O3 named iron(III) oxide?

Fe₂O₃ is named iron(III) oxide according to the basic ionic naming rules (nomenclature) used in chemistry. In this case, the name's first part is the cation element and the degree of the charge (III), and the second part is the anion element name combined with "ide."

Chemical nomenclature was developed so that systematic names could be created for chemical compounds. This helps to ensure that there will be no ambiguity regarding the compound that a written or spoken name represents. The name can also convey details about the chemistry or structure of a compound. The most frequently used nomenclature worldwide was developed by the International Union of Pure and Applied Chemistry, or IUPAC.