Which of the following metals forms a green colour coating due to corrosion?

Correct option is C

The correct answer is C Copper.

• Copper forms a green coating called patina due to corrosion.
• This occurs when copper reacts with atmospheric oxygen, carbon dioxide, and moisture, forming compounds like copper carbonate and copper hydroxide.
• Over time, this patina protects the underlying metal from further corrosion.

• Patina on copper is primarily a mix of copper carbonate and copper hydroxide.
•  This green layer is commonly seen on statues, roofs, and other copper structures.
•  Unlike rust (iron oxide), patina acts as a protective layer.
• Examples include the Statue of Liberty, which is green due to patina.
• Other metals like silver tarnish (black coating), and iron rusts (reddish-brown coating)