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BJU Chemistry Ch 11
Bob Jones Chemistry - Chapter 11
Term | Definition |
---|---|
adhesion | The attraction between the particles of a liquid and the particles of other materials. |
allotrope | One of two or more forms of a polymorphous element that exists in the same physical state. |
allotropic element | Pure elements that are polymorphous. |
amorphous solid | A solid in which the particles occur in random positions with no orderly pattern. |
boiling | A physical change from the liquid state to the gaseous state caused by the application of heat that occurs when the vapor pressure of a liquid equals the prevailing atmospheric pressure. |
boiling point | The temperature at which the vapor pressure of a liquid equals the applied atmospheric pressure. |
capillary action | The movement of a liquid up a narrow tube caused by adhesion between molecules in the walls of the tube and the molecules of the liquid. |
cohesion | The attraction between the particles of a liquid. |
condensation | A physical change from the gaseous state to the liquid state. |
critical pressure | The pressure required to liquefy a gas at its critical temperature. |
critical temperature | The highest temperature at which a gas can be liquefied. Each gas has its own characteristic critical temperature. |
crystal lattice | An extensive three-dimensional structure that represents the regular pattern of atoms or ions. |
crystalline solid | A solid in which particles occur in a regular repeating pattern. |
deposition | A physical change directly from the gaseous state to the solid state. |
dipole-dipole force | An intermolecular force; the attraction of the positive end of one polar molecule to the negative end of another polar molecule. |
dispersion force | An electrostatic attraction that arises between atoms or molecules because of the presence of instantaneous and induced temporary dipoles. It is the only intermolecular force acting on nonpolar molecules. |
distillation | A technique used to separate a mixture by evaporating its components at their boiling points and then condensing and collecting the vapors. |
dynamic equilibrium | A chemical equilibrium in which two or more opposing events occur at the same rate but result in no net change. |
evaporation | A physical change from the liquid state to the gaseous state that occurs at the surface of a liquid when the temperature is between the substance's freezing and boiling points. |
hydrogen bond | A special dipole-dipole force involving hydrogen and a highly electronegative element (fluorine, oxygen, or nitrogen). |
intermolecular force | An electrostatic attraction between molecules. It is much weaker than the bonds that form within molecules. |
lattice energy | The energy released when gaseous particles form crystals. It is expressed as a negative number. |
melting point | The temperature at which a solid turns into a liquid at 1 atm; the same temperature as the freezing point for pure solids. |
meniscus | The curved upper surface of a column of liquid that results from intermolecular attractions within the liquid and between the liquid and its container. |
normal boiling point | The temperature at which the vapor pressure equals 760 torr. |
phase diagram | A diagram summarizing the temperature and pressure conditions under which a pure substance exists as a solid, liquid, or gas. |
polymorphous | A substance (either an element or a compound) that can occur in more than one type of crystalline form. |
sublimation | A physical change from the solid state directly to the gaseous state. |
surface tension | The elastic "skin" that forms the surface of liquids. It is produced by the imbalance of intermolecular forces on the surface of a liquid. |
surfactant | A substance added to a liquid that acts to reduce the surface tension of that liquid by interfering with hydrogen bonds. |
triple point | The temperature and pressure at which the solid, liquid, and gaseous states of a substance exist in equilibrium. |
unit cell | The basic building block for any type of crystal; the section of a crystal lattice that contains one formula unit of the compound or one repeating segment of the overall lattice structure. |
vaporization | A physical change from the liquid state to the vapor or gaseous state. |
vapor pressure | Th pressure exerted by a vapor in equilibrium with its solid or liquid state at a specified temperature. |
viscosity | The ability of a liquid to resist flow; the amount of internal resistance. |