A pot exposed to moist air for a long time. It acquires a light, green coating. What is the vessel made of?

The correct answer is Copper.

Key Points

• When a copper vessel is exposed to moist air for a long time, it undergoes a chemical reaction with oxygen and moisture in the air, leading to the formation of a green coating called copper oxide.
• This green coating, known as patina, is a natural corrosion product that forms on the surface of copper due to oxidation.
• The formation of the green coating is a protective process that helps prevent further corrosion of the copper. It acts as a barrier between the copper surface and the surrounding air, protecting the underlying copper from further oxidation.

Additional Information

• Copper is a highly corrosion-resistant metal, which makes it suitable for various applications, including plumbing, electrical wiring, and the production of cookware and decorative items.
• The green patina formed on copper objects is often considered aesthetically pleasing and is valued for its unique appearance. It is commonly seen on copper roofs, statues, and other copper objects exposed to the environment over time.