Question

Aluminium is reactive than iron but when both are exposed to air, iron corrodes but aluminum doesn't why?

Answer 1

Iron and steel rust when they come into contact with water and oxygen. They rust faster in salty water or acid rain. Aluminium, on the other hand, does not corrode easily, because its surface is protected by a layer of aluminium oxide.
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Answer 2

Hello I can help you.

As you know aluminum is more reactive than iron. But when exposed to air, iron corrodes. It is because oxygen and moisture combine with iron and form iron-oxide, or rust. The rust is such a compound that is of no importance.
When aluminum is exposed to the air, it forms aluminum-oxide. It is not much different from aluminium and is not vey noticeable.

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