adhesive force | force of attraction between molecules of different chemical identities | | | | |
amorphous solid | (also, noncrystalline solid) solid in which the particles lack an ordered internal structure | | | | |
body-centered cubic (BCC) solid | crystalline structure that has a cubic unit cell with lattice points at the corners and in the center of the cell | | | | |
body-centered cubic unit cell | simplest repeating unit of a body-centered cubic crystal; it is a cube containing lattice points at each corner and in the center of the cube | | | | |
boiling point | temperature at which the vapor pressure of a liquid equals the pressure of the gas above it | | | | |
Bragg equation | equation that relates the angles at which X-rays are diffracted by the atoms within a crystal | | | | |
capillary action | flow of liquid within a porous material due to the attraction of the liquid molecules to the surface of the material and to other liquid molecules | | | | |
Clausius-Clapeyron equation | mathematical relationship between the temperature, vapor pressure, and enthalpy of vaporization for a substance | | | | |
cohesive force | force of attraction between identical molecules | | | | |
condensation | change from a gaseous to a liquid state | | | | |
coordination number | number of atoms closest to any given atom in a crystal or to the central metal atom in a complex | | | | |
covalent network solid | solid whose particles are held together by covalent bonds | | | | |
critical point | temperature and pressure above which a gas cannot be condensed into a liquid | | | | |
crystalline solid | solid in which the particles are arranged in a definite repeating pattern | | | | |
cubic closest packing (CCP) | crystalline structure in which planes of closely packed atoms or ions are stacked as a series of three alternating layers of different relative orientations (ABC) | | | | |
deposition | change from a gaseous state directly to a solid state | | | | |
diffraction | redirection of electromagnetic radiation that occurs when it encounters a physical barrier of appropriate dimensions | | | | |
dipole-dipole attraction | intermolecular attraction between two permanent dipoles | | | | |
dispersion force | (also, London dispersion force) attraction between two rapidly fluctuating, temporary dipoles; significant only when particles are very close together | | | | |
dynamic equilibrium | state of a system in which reciprocal processes are occurring at equal rates | | | | |
face-centered cubic (FCC) solid | crystalline structure consisting of a cubic unit cell with lattice points on the corners and in the center of each face | | | | |
face-centered cubic unit cell | simplest repeating unit of a face-centered cubic crystal; it is a cube containing lattice points at each corner and in the center of each face | | | | |
freezing | change from a liquid state to a solid state | | | | |
freezing point | temperature at which the solid and liquid phases of a substance are in equilibrium; see also melting point | | | | |
hexagonal closest packing (HCP) | crystalline structure in which close packed layers of atoms or ions are stacked as a series of two alternating layers of different relative orientations (AB) | | | | |
hole | (also, interstice) space between atoms within a crystal | | | | |
hydrogen bonding | occurs when exceptionally strong dipoles attract; bonding that exists when hydrogen is bonded to one of the three most electronegative elements: F, O, or N | | | | |
induced dipole | temporary dipole formed when the electrons of an atom or molecule are distorted by the instantaneous dipole of a neighboring atom or molecule | | | | |
instantaneous dipole | temporary dipole that occurs for a brief moment in time when the electrons of an atom or molecule are distributed asymmetrically | | | | |
intermolecular force | noncovalent attractive force between atoms, molecules, and/or ions | | | | |
interstitial sites | spaces between the regular particle positions in any array of atoms or ions | | | | |
ionic solid | solid composed of positive and negative ions held together by strong electrostatic attractions | | | | |
isomorphous | possessing the same crystalline structure | | | | |
melting | change from a solid state to a liquid state | | | | |
melting point | temperature at which the solid and liquid phases of a substance are in equilibrium; see also freezing point | | | | |
metallic solid | solid composed of metal atoms | | | | |
molecular solid | solid composed of neutral molecules held together by intermolecular forces of attraction | | | | |
normal boiling point | temperature at which a liquid’s vapor pressure equals 1 atm (760 torr) | | | | |
octahedral hole | open space in a crystal at the center of six particles located at the corners of an octahedron | | | | |
phase diagram | pressure-temperature graph summarizing conditions under which the phases of a substance can exist | | | | |
polarizability | measure of the ability of a charge to distort a molecule’s charge distribution (electron cloud) | | | | |
simple cubic structure | crystalline structure with a cubic unit cell with lattice points only at the corners | | | | |
simple cubic unit cell | (also, primitive cubic unit cell) unit cell in the simple cubic structure | | | | |
space lattice | all points within a crystal that have identical environments | | | | |
sublimation | change from solid state directly to gaseous state | | | | |
supercritical fluid | substance at a temperature and pressure higher than its critical point; exhibits properties intermediate between those of gaseous and liquid states | | | | |
surface tension | energy required to increase the area, or length, of a liquid surface by a given amount | | | | |
tetrahedral hole | tetrahedral space formed by four atoms or ions in a crystal | | | | |
triple point | temperature and pressure at which three phases of a substance are in equilibrium | | | | |
unit cell | smallest portion of a space lattice that is repeated in three dimensions to form the entire lattice | | | | |
vacancy | defect that occurs when a position that should contain an atom or ion is vacant | | | | |
van der Waals force | attractive or repulsive force between molecules, including dipole-dipole, dipole-induced dipole, and London dispersion forces; does not include forces due to covalent or ionic bonding, or the attraction between ions and molecules | | | | |
vapor pressure | (also, equilibrium vapor pressure) pressure exerted by a vapor in equilibrium with a solid or a liquid at a given temperature | | | | |
vaporization | change from liquid state to gaseous state | | | | |
viscosity | measure of a liquid’s resistance to flow | | | | |
X-ray crystallography | experimental technique for determining distances between atoms in a crystal by measuring the angles at which X-rays are diffracted when passing through the crystal | | | | |