A student has been collecting silver coins and copper coins. One day she observed a black coating on silver coins and a green coating on copper coins. Which chemical phenomenon is responsible for these coatings? Write the chemical name of black and green coatings.
The phenomena responsible for the formation of a coating on copper and silver objects is known as corrosion. Silver turns black due to the formation of silver sulphide while copper turns green due to the formation of a mixture of copper carbonate and copper hydroxide.
Lakhmir Physics (2020, 2021)