Test 2 Flashcards
surface tension
The energy required to increase the surface area of a liquid by a given amount
capillarity
A property that results in a liquid rising through a narrow space against the pull of gravity
viscosity
A measure of the resistance of liquid to flow
crystalline solid
Solid with a well-defined shape because of the orderly arrangement of the atoms, molecules, or ions.
amorphous solid
A solid that has a poorly defined shape because it lacks extensive molecular-level ordering of its particles.
lattice
The three dimensional arrangement of points created by choosing each point to be at the same location within each particle of a crystal; thus, the lattice consists of all points with identical surroundings
unit cell
The smallest portion of a crystal that , if repeated in all three directions, gives the crystals
coordination number
In a crystal, the number of nearest neighbors surrounding a particle. In a complex, the number of ligand atoms bonded to the central metal ion.
simple cubic unit cell
A unit cell in which a particle occupies each corner of a cube
body-centered cubic unit cell
A unit cell in which a particle lies at each corner and in the center of a cube
face-centered cubic unit cell
A unit cell in which a particle occurs at each corner and in the center of each face of a cube.
packing efficiency
The percentage of the available volume occupied by atoms, ions, or molecules in a unit cell
hexagonal closet packing
A crystalline structure based on the hexagonal unit cell in which the layers have an abab pattern.
cubic closet packing
A crystal structure based on the face-centered cubic unit cell in which the layers have an abcabc pattern.
x-ray diffraction analysis
An instrumental technique used to determine dimensions of crystal structure by measuring the diffraction patterns caused by x-rays impinging on the crystal
atomic solid
A solid consisting of individual atoms held together by dispersion forces; the frozen noble gases are the only examples.
molecular solid
A solid held together by intermolecular forces between individual molecules.
ionic solid
A solid whose unit cell contains cations and anions
metallic solid
A solid whose individual atoms are held together by metallic bonding
network covalent solid
A solid in which all the atoms are bonded covalently so that individual molecules are not present
electron-sea model
A qualitative description of metallic bonding proposing that metal atoms pool their valence electrons into a delocalized “sea” of electrons in which the metal cores are submerged in an orderly array.
band theory
An extension of molecular orbital theory that explains many properties of metals and other solids, in particular, the differences in electrical conductivity of conductors, semiconductors, and insulators.
valence band
In band theory, the lower energy portion of the band of molecular orbitals, which is filled with valence electrons.
conduction band
In band theory, the empty, higher energy portion of the band of molecular orbitals into which electrons move when conducting heat and electricity
