Question

Paheli bought a statue made of copper. To her surprise, it acquired a dull green coating after a couple of months. Explain the reason. ​

Answer 1

When copper is exposed to air, it slowly loses its shining brown surface and gains a green coating. ​This green coating appears due to the formation of $Cu(OH{)}_2$ (copper hydroxide) and $CuC{O}_3$ (copper carbonate).