Assumption of Kinetic Theory of Gases

1. All gases are made of molecules moving randomly in all the directions.
2. The size of a molecule in much smaller than the average separation between  

  the molecules.
3.The molecules exert no force on each other or on the walls of the of the 

 container except during collision.
4.All collisions between two molecules or between a molecule and a wall are  perfectly elastic. Also, the time spend during a collision is negligibly small.
5.The molecules obey Newton's law of motion.