Rahul has been collecting copper coins and silver coins. One day he observed a green coating on copper coins and a black coating on silver coins. State the chemical phenomenon responsible for these coatings and also write chemical names of each coating.

Copper coins and silver coins get a coating because of the phenomenon of corrosion.
Copper coins react with carbon dioxide and moisture in the atmosphere to form copper
carbonate.
Silver coins react with sulphur in the atmosphere to form a coating of silver sulphide.