# Kinetic theory

mathematical model explaining macroscopic properties of gases in microscopic terms

Kinetic theory or kinetic theory of gases attempts to explain overall properties of gases, such as pressure, temperature, or volume, by considering their molecular composition and motion. The theory basically states that pressure is not caused by molecules pushing each other away, like earlier scientists thought. Instead, pressure is caused by the molecules colliding with each other and their container. Kinetic theory is also known as kinetic-molecular theory or collision theory.

There are three main components to kinetic theory:[1]

• No energy is gained or lost when molecules collide
• The molecules in a gas take up a negligible (able to be ignored) amount of space in relation to the container they occupy
• The molecules are in constant, linear motion.

## References

• The Mathematical Theory of Non-uniform Gases : An Account of the Kinetic Theory of Viscosity, Thermal Conduction and Diffusion in Gases, Sydney Chapman, T. G. Cowling

The main postulate of this theory are-- 1.The particles attract each other with a force. This force is called cohesive force if the particles are of same kind and adhesive force when particles are of different kinds. 2. All matter is composed of small particles called molecules. (Atoms or ions as the situation demands). 3. The particles are in a state of unending motion (continuous motion) and as such have kinetic energy. 4. with the supply of heat energy (thermal energy) to matter, the kinetic energy of a particle increase, i.e., they start moving more vigorously. Reverse happens if the matter is cooled.i.e., heat energy is taken out of it. 5. The force of attraction between the particles decreases, if the distance between them increases and vice versa.

Last updated Sat,16 May 2020 9:00 pm By Rachit Vishwakarma ..................................