Oxidation is a process in which the oxygen molecule reacts with either a metal or a nonmetal to form an oxide. The oxide thus formed is called a metallic or non-metallic oxide respectively. Oxides formed with a metal are called basic oxides while oxides of a non-metal are called acidic oxides. Acidic oxides will react with water to form acids. This is one of the ways of producing acids. The best example of this process is the oxidation process involved in the rusting of iron. During the monsoon, iron tends to rust easily. This is due to the moisture in the air. When iron comes in contact with moist air, the oxygen molecules from the moist air (water vapour) react with the iron forming an oxide, which appears as rust.