Question

(b)When a copper surface is exposed to air for a long time, it develops a greenish layer on its surface.Why?

Answer 1

Answer:

due to corrosion

Explanation:

when a metal surface is exposed with moisture and oxygen then it's start corode and this process is called as corrosion

Answer 2

Answer:

it is due to corrosion

Explanation:

When any copper surface is exposed to air, the metal reacts with gases from atmosphere to form Copper Carbonate and Copper hydroxide due to this, the metal develops greenish layer on its surface.