What do you mean by corrosion? How can you prevent it ?

Explanation

a) Corrosion : When some metals are exposed to moisture, acids, etc. they tarnish due to the formation of respective metal oxide on their surface. This process is called corrosion.
Example to corrosion :
Tarnishing on silver ware.
a. `4Ag+2H_(2)S+O_(2)rarr 2Ag_(2)S+2H_(2)O`
b. (Black coating (due to `Ag_(2)S`) forms on silver articles)
Corrosion of copper :
c. `2Cu+O_(2)rarr 2CuO`
d. (Green coating (due to CuO) on copper)
b) Effect of corrosion : Corrosion is the oxidative deterioration of a metal.
1) Corrosion causes damage to car bodies, bridges, iron railings, ships etc.
2) And to all other objects that are made of metals are effected by corrosion.
3) Especially corrosion of iron is a serious problem.
c) Prevention of corrosion : Corrosion can be prevented or minimized by shielding the metal surface from oxygen and moisture.
1) It can be pevented by painting, oiling, greasing, galvanizing, chrome plating etc.
2) Alloying is also a very good method of improving properties of metal.
Eg : steel, bronze, brass.