Oxidation states simplify the process of determining what is being oxidized and what is being reduced in redox reactions. it would be useful to review with the following concepts:
• oxidation and reduction in terms of electron transfer
• electron-half-equations
To illustrate this concept, consider the element vanadium. Vanadium forms a number of different ions - for example, V2+ and V3+. The 2+ ion will be formed from vanadium metal by oxidizing the metal and removing two electrons: