Aluminium

Aluminium reacts with oxygen in air to form an oxide layer covering the metal surface. And it is impermeable to the moisture and oxygen in atmosphere. However, iron cannot behave similar function as aluminium because it reacts with moisture and oxygen in air to form rust which is more brittle than the aluminium oxide layer. Hence, despite that fact that aluminium loses electrons more readily than iron, the corrosion resistance of aluminium is still higher than that of iron.