The concept of temperature as a consequence of thermal equilibrium is introduced. The interdependence of pressure, temperature and volume through the equation of state of an ideal gas is examined. Latent heat and its relation to bond energies are discussed. Gases Elementary kinetic theory of a non-interacting gas is used to introduce the equivalence of thermal and kinetic energy. Elastic collisions between molecules are treated in a simple manner and the idea of a mean free path introduced.
Strong emphasis is placed on the random nature of molecular motion.
The dominance of potential energy and the translation invariance of crystalline solids are discussed for short range, weakly bound van der Waals solids and long range, strongly bound ionic salts. Static deformations and elastic moduli are introduced. Liquids and Liquid Crystals Liquids are treated as excessively disordered solids and as strongly interacting gases. The roll of directional order is brought in via liquid crystals. A very gentle discussion of order, disorder and entropy in the three phases is given.