| A | B |
|---|
| mass | the amount of "stuff" in an object |
| matter | anything that occupies space and has mass |
| kinetic energy | energy possessed by an object that is moving |
| potential energy | energy that is stored |
| closed system | a system that must use and reuse everything in it because nothing can enter or leave this system |
| open system | a system in which both matter and energy are exchanged between the system and environment (a living organism is an example of an open system) |
| steady state | a balanced condition in a system because a substance (or energy) is entering and leaving at the same rate |
| Law of Conservation of Matter | matter can neither be created nor destroyed, it can just be rearranged |
| Law of Conservation of Energy | energy can neither be created nor destroyed, it can just be transformed from one form to another |
| mechanical energy | energy of movement |
| heat energy | a form of energy that flows from one body to another because of a temperature difference between them due to the difference in the motion of molecules |
| radiant energy | the energy of electromagnetic waves, including light |
| electrical energy | the energy of electrons in motion |
| magnetic field | a region in space in which a magnet or compass needle will experience a force |
| chemical energy | the energy that is stored in the chemical bonds that hold molecules together |
| nuclear energy | energy liberated by a nuclear reaction, such as fission or fusion |
| calorie | the amount of energy necessary to raise the temperature of 1 gram of water 1 Celsius degree |
| Btu | the amount of heat required to raise the temperature of 1 pound of water 1 degree Fahrenheit |
| efficiency | a ratio of the desired output (work or energy) of a machine |
