|
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
|
|
|
|
|