Question

Why sodium is kept in kerosene oil and not in any other oil or liquid.

Answer 1

sodium reacts very vigourously with oxygen in air to form sodium oxide.
this is why sodium cannot be left out in the open and is kept immersed in kerosene

Answer 2

Sodium is highly reactive . So it's kept immersed in kerosene oil to prevent its reaction with oxygen , moisture and carbon dioxide of air to prevent accidental fires .