Kinetic Molecular Theory (KMT)
1. The volume of the particles of a gas can be assumed negligible (zero).
2. The particles are in constant motion. The collisions of the particles with the walls of the container are the cause of the pressure exerted by the gas.
3. The particles are assumed to exert no forces on each other.
4. The average kinetic energy of gas particles is assumed to be directly proportional to the Kelvin temperature of the gas.