Explain Kinetic theory?

Answer 1

It is just basically the idea the molecules are constantly in motion. As the temperature increases, the motion of the molecules increases. As the molecules of a solid vibrate more and more with increasing temperature, they eventually vibrate enough to break the forces between molecules, and the solid melts. Same thing with liquids vaporizing. In a sample of a gas, as the temperature increases, the average kinetic energy of the molecules increases.

At what level do you need the explanation? In a chemistry book, you should be able to find a graph showing the distribution of kinetic energies of molecules at different temperatures. There should be an equation which describes that distribution, as well...