Oxidation states simplify the process of determining what is being oxidized and what is being reduced in redox reactions. However, it would be useful to review and be familiar 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: