Why sodium is kept is kerosene..?

Sodium is a very active element that combines with oxygen at room temperature and burns with a brilliant golden-yellow flame. It reacts violently with water to produce hydrogen gas, which may be ignited by the heat of the reaction. To avoid having sodium react with oxygen or water vapor in the air, it is usually stored under kerosene, naphtha, or some other organic liquid with which it does not react. Sodium also reacts readily with most nonmetals and dissolves in mercury to form a sodium amalgam.