Spilled mercury on aluminum causes rapid and severe corrosion that is very difficult to control.

• A. True
• B. False
• C. Mercury improves corrosion resistance
• D. Mercury forms a protective layer

Answer: (A)

Aluminum relies on a thin oxide layer to protect it from corrosion. Mercury readily wets and interacts with that surface, and it can dissolve into or disrupt the protective oxide, effectively breaking down the barrier and forming an amalgam at the interface. Once the oxide is compromised, the underlying aluminum is exposed to moisture and the environment, so corrosion can proceed rapidly. The liquid nature of mercury means it can spread across the metal and stay in contact with fresh aluminum, making cleanup and mitigation difficult and prolonging the damage. Because of these factors, spilled mercury on aluminum can lead to fast, widespread, and hard-to-control corrosion.