Give reasons for the following observation :

The smell of hot sizzling food reaches you several metres away, but to get the smell from cold food you have to go close.

Suggest a method to liquefy atmospheric gases.

Comment upon the following :

Rigidity, compressibility, fluidity, filling a gas container, shape, kinetic energy and density.

Give reasons : A wooden table should be called a solid.

For any substance, why does the temperature remain constant during the change of state ?