Question

What is rusting of iron?

Answer 1

here is ur anwer- 

. the red or orange coating that forms on the surface of ironwhen exposed to air and moisture, consisting chiefly of ferric hydroxide and ferric oxide formed by oxidation. 2. any film or coating on metal caused by oxidation.

Answer 2

Iron comes into contact with the wetness (humidity) in air and gets oxidized.

A thin layer of Iron oxide is formed on the surface. That is in brown color. It is not possible to get back Iron from Iron oxide, by using normal physical means of heating, filtering etc. So it is a chemical change.