When the oxygen atom splits, water makes the element iron react with oxygen. This causes the iron to lose electrons while oxygen gains electrons during the early stages of rusting. The ferrous and ferric ions respond to ferrous hydroxide, ferric hydroxide, and hydrogen with water to form rust. There have been several experiments to prove the same. When a nail is placed in a container containing air and water, it will rust in no time. But if the nail is placed in water with a layer of oil on the water surface, it blocks the entry of air and prevents rusting. Similarly, if the container with the nail contains calcium chloride and is covered by a lid, it removes the water vapour from the air and avoids rusting.