TABLE OF CONTENTS So many of the properties of matter, especially when in the gaseous form, can be deduced from the hypothesis that their minute parts are in rapid motion, the velocity increasing with the temperature, that the precise nature of this motion becomes a subject of rational curiosity.
James Clark Maxwell, 1860
This chapter has to do with the rattling about of individual particles molecules, atoms, electrons and their collisions with each other. This is the level at which nature really works in a gas and is the essence of kinetic theory. How frequently does a given particle collide with its neighboring particles, that is, how many collisions per second does a particle in a gas experience? On the average, how far does a particle move in between collisions? Finally, what is the velocity of a given particle, on the average? Answers are given in this chapter. The reason that we are interested in such answers is that energy transfer between different modes of energy (translational, rotational, vibrational, and electronic) takes place by way of particle collisions. Chemical reactions also occur as a result of particle collisions. Collisions take time to occur, especially a sufficient number of collisions to bring about the energy transfer and chemical reactions. If the gas on the whole is simply sitting around, going nowhere, we can simply wait for the required number of particle collisions to occur. After that, the gas will be at equilibrium, with the equilibrium thermodynamic and chemical properties discussed in the preceding...
