Why does aluminum (Al) metal not undergo corrosion like iron does?

• A. Aluminum forms a thin, protective oxide layer that prevents further oxidation.
• B. Aluminum is less reactive than iron and does not react with oxygen.
• C. Aluminum reacts with water to form a soluble compound that washes away.
• D. Aluminum corrodes rapidly but the corrosion is not visible.

Answer: (A)

Verified step by step guidance

1. Understand the concept of corrosion: Corrosion is the process where metals react with oxygen and moisture in the environment, leading to the formation of oxides or other compounds that degrade the metal.
2. Recognize that iron corrodes by forming rust (iron oxide), which is porous and flaky, allowing oxygen and water to continue reacting with the metal underneath.
3. Know that aluminum, when exposed to oxygen, forms a very thin but dense and adherent layer of aluminum oxide (Al\_2O\_3) on its surface.
4. This aluminum oxide layer acts as a protective barrier that prevents further oxygen and moisture from reaching the underlying metal, effectively stopping further corrosion.
5. Therefore, aluminum does not corrode like iron because its oxide layer is protective and prevents ongoing oxidation, unlike the porous rust layer on iron.