Which statement correctly describes mercury's interaction with aluminum?

• A. Mercury does not react with aluminum
• B. Mercury only reacts with aluminum at high temperatures
• C. Mercury can cause rapid and severe corrosion on aluminum
• D. Mercury forms a protective coating on aluminum

Answer: (C)

Mercury damages aluminum by breaking down its protective oxide film and forming an amalgam with the metal, which allows corrosion to advance rapidly. Aluminum relies on a thin oxide layer to resist corrosion; when mercury comes into contact, it wets the surface, penetrates that oxide, and the metal and mercury mix, leading to swift and severe deterioration. This can happen at ordinary temperatures, so it’s not limited to high-temperature conditions. Mercury does not produce a protective coating on aluminum; it does the opposite by removing the barrier and accelerating corrosion.