Basic assumptions of kinetic theory

1. A gas consists of a very large number of molecules of negligible size which are in a state of constant random motion. Pressure results from molecular collisions with the container walls.

2. Collisions between molecules or between a molecule and the walls of the container are perfectly elastic, i.e., there is no change in the molecular kinetic energy in a collision.

3. Intermolecular forces are negligible aside from collisions. Between collisions, a molecule travels in a straight line at constant speed.

4. The kinetic energy of a gas molecule is given by E = mu2/2, where m and u are the molecular mass and speed, respectively.