Why do we apply paint on iron articles?
We apply paint on iron articles to prevent them from corrosion. When iron articles are left for some time, they are attacked by substances around them such as moisture and acids. This causes the iron to get coated with a reddish brown powder, commonly known as rusting.
Corrosion causes damage to car bodies, bridges, and iron railings. It is a serious problem, and an enormous amount of money is spent every year to replace damaged iron. Paint acts as a protective layer that stops the substances around the iron from attacking it, thereby preventing the formation of rust.
Explanation
The answer is derived from Section 1.3.1 'Corrosion' of the provided text. The textbook explains that iron articles get coated with a reddish brown powder (rust) when attacked by substances like moisture and acids. It further states that corrosion causes damage to objects like car bodies and bridges, costing money to replace them. Applying paint prevents this contact, thus stopping corrosion.