| Term | Definition |
| Quality | mass of vapor/total mass |
| Isothermal Process | a process at constant temperature |
| Macroscopic Energy | Energies associated with the entire body under investigation (kinetic and potential) |
| Microscopic Energy | Sensible, Latent, Chemical, Nuclear Energies |
| Sensible Energy | Translational, rotational, and kinetic energy of the molecules in the body. |
| Latent Energy | Energy associated with bonds between molecules in body |
| Chemical Energy | Energy associated with bonds between atoms |
| Nuclear Energy | Energy associated with bonds between subatomic particles in atom nucleus. |
| Internal Energy | Sum of all forms of microscopic energy |
| Thermal Energy | Sensible energy and Latent energy |
| Boundary | Separates closed system from surroundings |
| Control Surface | Boundary of open system |
| Heat | Energy transfer without mass driven by temp difference |
| Work | Energy transfer without mass driven by any difference but temp |
| Adiabatic Process | a process that takes place with out a transfer of heat between the system and its surroundings. |
| Property | Any characteristic of a system |
| State | The total set of properties which define the condition of the system |
| State Postulate | The state of a simple, compressible system is completely defined by two independent intensive properties. (a simple compressible system is a system under no magnetic, electrical or gravitational motion effects) |
| Process | Any change that a system undergoes from one state to the next. |
| Equilibrium States | All driving potentials are balanced |
| Thermal Equilibrium | Uniform temp throughout. |
| Mechanical Equilibrium | No unbalanced pressures |
| Phase Equilibrium | The quality of matter in each phase is constant. |
| Chemical Equilibrium | The quantity of matter in each species in the reaction is constatnt |
| Isobaric Process | a process that takes place at a constant pressure |
| Reversible Process | A process who's path remains infinitely close to equilibrium states at all times |
| Isometric Process (Isochoric) | A process that takes place at a constant volume |
| Cycle | A single process, or series of processes that ultimately bring the system back to its original state |
| First Law | Energy is a property and it is conserved |
| Second Law | Heat has a quality and all real processes degrade that quality |
| Third Law | Entropy at 0 K is 0 |
| First Law Efficiency | Desired Effect/Required Input |
| Conduction | Heat transfer by molecules shaking adjacent molecules |
| Convection | Heat Transfer by fluid motion |
| Radiation | Heat Transfer by electromagnetic waves |
| Boundary Work | Work associated with moving a system boundary |
| Polytropic Process | A process where pV^n=constant. |
| Isolated System | A closed system with no energy exchange between system and surroundings. (type of closed system) |
| Energy | The ability or potential to cause change |
| Path | The series of states through which a system passes during a process. |
| 0th Law | If two bodies are in thermal equilibrium with a third body, then they are in thermal equilibrium with each other. |
| Pure Substance | A substance with a fixed chemical composition throughout. |
| c (constant v) | change in u/change in T |
| c (constant p) | change in h/change in T |