Question

what do you mean by corrosion How can we prevent it

Answer 1

corrosion is the process in which metals are eaten up gradually by the action of air ,moisture or a chemical ( such as an acid ) on their surface .

prevention --- a lot of money has to be spent every year to prevent the corrosion of iron and steel objects, and to replace the damage iron and steel structures. 

Answer 2

$\red{ {\mathbb{ \star \: Corrosion}}}$ When some metals are exposed to moisture,acids etc..., they tarnish due to the formation of respective metal oxide on their surface.Thi process is called corrosion.

E.g.

1. The black coating on silver.
2. Green coating on copper.

$\implies$ Corrosion can be prevented or at least minimised by shielding the metal surface from oxygen and moisture.

$\implies$ It can be prevented by painting, oiling,greasing,galavanizing,chrome plating (or) making alloys.