Rusting

•  a red brown flaky substance called rust . 
• The process by which rust appears on iron surfaces is known as rusting of iron .

Iron (fe ) + oxygen ( o2 from air)+ water (H2o) —-> rust (Fe203) from oxide

• It is necessary to have both water and oxygen present for rusting to take place. 
• So, rusting would not take place in a dry place .
• Hence, rusting can be prevented by not letting iron items come into contact with water or oxygen.
• We can prevent rusting by applying a coat of paint or grease regularly to the object.
• Another way is to deposit a layer of metal like chromium or zinc on the iron.