| A | B |
|---|
| dipole-diple forces | attractive forces between polar molecules |
| hydrogen bonds | attractive forces between hydrogen and either oxygen, nitrogen, or fluorine |
| dispersion forces | attractive forces between all molecules, caused by random dispersion of electrons |
| crystalline solids | solids that have particles in a regular repeating pattern |
| amorphous solids | solids that have randomly arranged particles |
| melting | changing from a solid to a liquid |
| freezing | changing from a liquid to a solid |
| sublimation | changing from a solid to a gas |
| deposition | changing from a gas to a solid |
| crystal lattice | a crystal's 3-D pattern |
| unit cell | smallest repeating section of a crystal lattice |
| polymorphous | able to form more than one crystalline shape |
| allotropic | pure elements that are polymorphous |
| allotropes | different forms of polymorphous elements |
| lattice energy | energy released when gaseous particles form crystals |
| atomic crystals | individual atoms (Noble gases) |
| covalent molecular crystals | covalently bonded molecules held together by intermolecular forces |
| covalent network cystals | individual atoms bound together by covalent bonds |
| ionic crystals | repeating network of ions defined by the unit cell |
| metallic crystals | positive metal ions surrounded by a sea of electrons |
| cohesion | attraction between paricles of a liquid |
| adhesion | attraction between a liquid and other materials |
| surface tension | elastic "skin" on the surface of liquids, produced by an imbalance of molecular forces |
| surfactants | surface-active agents; break down surface tension |
| viscosity | a liquid's ability to resist flowing |
| meniscus | a concave surface caused by adhesion with the container |
| capillary action | when a liquid rises up a tube, caused by adhesion |
| diffusibility | the ability of a liquid to mix spontaneously with another liquid |
| permeability | ability of a liquid to move through the spaces between particles |
| vaporization | changing from a liquid to a gas |
| condensation | changing from a gas to a liquid |
| evaporation | vaporization in a nonboiling liquid |
| vapor pressure | pressure exerted by evaporated molecules over a liquid |
| dynamic equilibrium | a condition in which two opposing forces occur at exactly the same rate |
| boiling | a rapid change between the liquid and gaseous states in which the vapor pressure = atmospheric pressure |
| distillation | the use of the processes of vaporization and condensation to separate mixtures |
| phase diagram | a graphical summary of temperature and pressure conditions in which a substance exists as a solid, liquid, or gas |
| triple point | point at which all three phases exist |
| critical temperature | the highest temperature at which a gas can be liquefied |
| critical pressure | pressure required to liquefy a gas at its critical temperature |
| cryogenics | the science of the very cold |
| cryonics | freezing and storing human bodies in hopes of bringing them back to life |
