| A | B |
|---|
| temperature | a measure of how hot (or cold) something is; specifically, a measure of the average kinetic energy of the particle in an object |
| thermal expansion | the increase in volume of a substance due to an increase in temperature |
| absolute zero | the lowest possible temperature (0 K, -237°C) |
| heat | the transfer of energy between objects that are at different temperatures; energy is always transferred from higher-temperature objects to lower-temperature objects until thermal equilibrium is reached; also the amount of energy that is transferred between objects that are at different temperatures |
| thermal energy | the total energy of the particles that make up an object |
| thermal equilibrium | the point at which two objects reach the same temperature |
| conduction (thermal) | the transfer of thermal energy from one substance to another through direct contact; conduction can also occur within a substance |
| conductor (thermal) | a substance that conducts thermal energy |
| convection | the transfer of thermal energy by the movement of a liquid or a gas |
| convection current | the circular motion of liquids or gases due to density differences that result from temperature differences |
| insulator (thermal) | a substance that does not conduct thermal energy well |
| greenhouse effect | the natural heating process of a planet, such as the Earth, by which gases in the atmosphere trap thermal energy |
| radiation | the transfer of energy through matter or space as electromagnetic waves, such as visible light and infrared waves |
| specific heat | the amount of energy needed to change the temperature of a certain mass by 1°C |
| heat | the transfer of energy between objects that are at different temperatures; energy is always transferred from higher-temperature objects to lower-temperature objects until thermal equilibrium is reached; also the amount of energy that is transferred between objects that are at different temperatures |
| calorie | the amount of energy needed to change the temperature of .001 kg of water by 1°C; 1 calorie is equivalent to 4.184 J |
| kilocalorie | the unit of energy equal to 1,000 calories; the kilocalorie can also be referred to as the Calorie, which is the unit of energy listed on food labels |
| states of matter | the physical forms in which a substance can exist; states include solid, liquid, gas, and plasma |
| change of state | the conversion of a substance from one physical form to another |
| physical change | a change that affects one or more physical properties of a substance; many physical changes are easy to undo |
| chemical change | a change that occurs when one or more substances are changed into entirely new substances with different properties; cannot be reversed using physical means |
| insulation | a substance that reduces the transfer of thermal energy |
| active solar heating | a solar-heating system consisting of solar collectors and a network of pipes that distributes energy from the sun throughout a building |
| passive solar heating | a solar-heating system that relies on thick walls and large windows to use energy from the sun as a means of heating |
| heat engine | a machine that uses heat to do work |
| thermal pollution | the excessive heating of a body of water |
