Question

Why na is stored in kerosene oil al is highly reactive metal even then it is used in making cooking utensil?

Answer 1

Na is more reactive than Al. Na when kept in air, reacts violently with oxygen whereas Al does not.

Answer 2

Sodium is a highly reactive metal. It reacts vigorously with oxygen as well as water. Hence it is stored in kerosene.
Aluminium is highly reactive metal. When aluminium is exposed to air it reacts with oxygen and forms a white thin layer of aluminium oxide on its surface. This layer forms protective coating on aluminium and prevents the reaction of aluminium with oxygen. Aluminium metal with this protective layer is used for making cooking utensils.
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