Which of the following metals does not corrode in the presence of air and water?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → Gold
Gold is one of the least reactive metals; it does not react with air or water, so it keeps its shine for centuries.
Why the other options are incorrect
Option (2) Copper — Incorrect. In moist air it slowly gets a green coating of basic copper carbonate.
Option (3) Aluminium — Incorrect. It reacts with air to form a thin layer of aluminium oxide on its surface.
Option (4) Zinc — Incorrect. It is more reactive than iron and corrodes in moist air; this is why it protects iron in galvanisation.