Thermodynamics is the description of thermal properties of matter in bulk. The study of phenomena involving the transfer of heat energy and allied processes form the subject matter. The fundamental description of the properties of matter in bulk, such as temperature, heat energy, etc., are given by statistical mechanics. For equilibrium states of a system the results of statistical mechanics give us the laws of thermodynamics<\/a>. These laws were empirically enunciated before the development of statistical mechanics. Taking these laws as axioms, a logical buildup of the subject of thermodynamics is possible.<\/p>\n Thermodynamic Coordinates<\/a> The macroscopically and directly observable quantities for any state of a physical system are the thermodynamic coordinates of that state. As an example, the pressure p and volume V of a gas can be taken as thermodynamic coordinates. In more general situations, other coordinates, such as magnetization and magnetic field, surface tension and area, may be necessary. The point is that the thermodynamic coordinates uniquely characterize the macroscopic state<\/a> of the system.<\/p>\n Two bodies are in thermal contact if there can be free flow of heat between the two bodies.<\/p>\n A body is said to be in adiabatic isolation if there can be no flow of heat energy into the body or out of the body into the environment. In other words, there is no exchange of heat energy with the environment.<\/p>\nDefinitions<\/h3>\n
Thermal Contact<\/h3>\n
Adiabatic Isolation<\/h3>\n
Thermodynamic Equilibrium<\/h3>\n