- Boltzmann constant
- constant with the value k = 1.38×10−23 J/K, which is used in the ideal gas law
- cyclical process
- process in which a system is brought back to its original state at the end of every cycle
- entropy
- measurement of a system's disorder and how much energy is not available to do work in a system
- first law of thermodynamics
- states that the change in internal energy of a system equals the net energy transfer by heat into the system minus the net work done by the system
- heat engine
- machine that uses energy transfer by heat to do work
- heat pump
- machine that generates the heat transfer of energy from cold to hot
- ideal gas law
- physical law that relates the pressure and volume of a gas to the number of gas molecules or atoms, or number of moles of gas, and the absolute temperature of the gas
- internal energy
- sum of the kinetic and potential energies of a system’s constituent particles (atoms or molecules)
- pressure
- force per unit area perpendicular to the force, over which the force acts
- second law of thermodynamics
- states that the total entropy of a system either increases or remains constant in any spontaneous process; it never decreases
- thermal efficiency
- ratio of useful energy output to the energy input
- thermal equilibrium
- condition in which heat no longer transfers energy between two objects that are in contact; the two objects have the same temperature
- zeroth law of thermodynamics
- states that if two objects are in thermal equilibrium, and a third object is in thermal equilibrium with one of those objects, it is also in thermal equilibrium with the other object