A metal 'X' acquires a green colour coating on outer surface on exposure to air.
(i) Identify the metal 'X' and name the process responsible for this change.
(ii) Name and write chemical formula of the green coating formed on the metal.
(iii) List two important methods to prevent the process.

Explanation

(i) The metal is copper. The process is corrosion.
(ii) Copper carbonate `(CuCO_(3))`
(iii) (a) It should be coated with tin.
(b) It should be mixed with other metals to form alloys.