Question

Why does copper become green during rainy season?

Answer 1

Answer:

Copper reacts with Oxygen in air which reacts with the rain and it produces Copper Oxide. CuO is green in colour.

Answer 2

Answer:

Due to corrosion

Explanation:

During the rainy season because of the high humidity copper begins to corrode and react with atmospheric gases and moisture to form copper hydroxide and copper carbonate. Copper carbonate gives the green colour coating to the surface of the metal .

2Cu + $O_{2}$ + $H_{2}$O + C$O_{2}$ = Cu(O$H_{2}$) + CuC$O_{3}$

Hope this helped :)