Kinetic Molecular Theory of Gases

•  A gas consists of very small microscopic particles called ‘molecules’. Depending upon the nature of      gas each gas molecule may consists of an atom or group of atoms. Molecules are in a state of      continuous motion.

• All the molecules of a gas are in stable state and are considered identical.

•  Any finite volume of a gas consists of very large number of molecules.

            At S.T.P. there are 3 × 10²⁵ molecules in a cubic meter.

• The molecules are wide separated from each other as compared to their own dimensions.

•  The diameter of a molecule is about  3 x 10^-10 meter.

• Gas molecules move in straight line in all possible directions (random movement) with various

speeds.

•  Gas molecules collide with each other and with the walls of container. Their collisions are perfectly      elastic in nature.

• Gas molecules when collide with the walls of container, they transfer their momentum which appears      as pressure of gas.

•  Molecules of an ideal gas exert no force of attraction or repulsion on one another except during      collision.

• The average kinetic energy of gas molecules is directly proportional to absolute temperature.

•  At a given temperature, the molecules of all gases have the same kinetic energy.

•  Newtonian mechanics is applicable to molecular motion.