| A | B |
|---|
| kinetic energy | the energy an object has because of its motion |
| gas pressure | results from the force exerted by a gas per unit surface area of an object |
| evaporation | the process in which molecules of a liquid escape from the surface of a liquid that is not boiling |
| boiling point | temperature at which the vapor pressure of a liquid is just equal to the external pressure |
| crystal | sample in which particles are arranged in an orderly, repeating, three-dimensional pattern |
| allotrope | two or more different molecular forms of the same element in the same physical state |
| melting point | the temperature at which a solid changes into a liquid |
| pascal (Pa) | the SI unit of pressure |
| amorphous solid | solid lacking an ordered internal structure |
| atmospheric pressure | results from the collisions of atoms and molecules in air with objects |
| barometer | device used to measure atmospheric pressure |
| glass | transparent fusion product of inorganic substance that have cooled to a rigid state without crystallizing |
| kinetic theory | all matter consists of tiny particles that are in constant motion |
| normal boiling point | the boiling point of a liquid at a pressure of 101.3 kPa |
| phase diagram | graph representing the relationships among the solid, liquid, and vapor states of a substance in a sealed container |
| standard atmosphere | pressure required to support 760 mm of mercury at 25°C |
| sublimation | change of a substance from a solid to a vapor without passing through the liquid state |
| triple point | the only set of conditions at which all three phases of a substance can exist in equilibrium with one another |
| unit cell | smallest group of particles within a crystal that retains the geometric shape of the crystal |
| vacuum | an empty space with no particles and no pressure |
| vaporization | the conversion of a liquid to a gas or a vapor |
| vapor pressure | a measure of the force exerted by a gas above a liquid |
