Question

A green layer is gradually formed on copper plate left exposed to air for a week in bathroom. what could this gram substance be?

Answer 1

this green substance is corrosion which formed by the action of air and moisture on copper's surface.It is basic copper carbonate (CuCO3).

Answer 2

Hey buddy here is your answer :

This gram substance is formed due to corrosion by moisture and other chemicals.
This green substance is Copper Carbonate
( CuCO3 ) This green layer is also called patina.

Hope it helps you mate