6.2.1 Describe the kinetic theory in terms of the movement of particles whose average energy is proportional to temperature in Kelvin.

Kinetic theory is basically defined by particles which make up chemical elements/compounds are in constant random motion. This are rapidly moving particles which frequently collide with each other and the walls of the container. As both temperature and kinetic energy are proportional, increasing the temperature (in Kelvins) will in turn increase the kinetic energy or the movement of particles.

The picture to the right illustrates the kinetic theory with ball bearings acting as particles, the cylinder and the polystyrene  acting as the container and a motor which generates the heat powered by electricity from the battery pack. Increasing the voltage is an analogy to increasing temperature and from the kinetic theory the ball bearings move faster and collide more frequently with the walls and with each other pushing the polystyrene up accordingly increasing the volume. Not all particles contain the same amount of kinetic energy. An average is taken .

The reason Kelvin is used instead of Celsius is because in 0 degrees Celsius the particles still have kinetic energy. Absolute zero refers to the temperature being -273Kelvin to completely stop the movement of the particles. This has not been achieved yet.