gases are made up of a large number of small spherical molecules, in random motion , that have only elastic collisions with each other and with the walls of the container

a model of an ideal gas that treats it as a collection of molecules undergoing motion according to Newton's laws of classical mechanics and predicts macroscopic quantities such as pressure and temperature in terms of molecular properties, such as the velocity of the molecules.

A rough approximation of how gases work, that is quite accurate in everyday conditions. According to the kinetic theory, gases are made up of tiny, round molecules that move about in accordance with Newtonâ€(tm)s Laws, and collide with one another and other objects elastically. We can derive the ideal gas law from the kinetic theory.