Sodium metal is kept under?

_____ discovered inert gases.

A mixture of water and alcohol can be separated by?

Who was the inventor of electron microscope?

The region covered by water is known as

One fathom is equal to

Joule is the unit of

Why is gravity so weired?

The weight of an object is due to ___?

The direction of acceleration in uniform circular motion is along the ____?

How many internal reflections of ligh take place in the formation of primary rainbow?