INTRO TO SOLIDS Flashcards
Most [] crystals have high melting points, an indication of the strong cohesive forces holding the ions together.
ionic
In a [], the lattice points are occupied by molecules, and the attractive forces between them are van der Waals forces and/or hydrogen bonding.
molecular crystal
They are composed of charged species and (2) anions and cations are generally quite different in size
ionic crystals
[] commonly refers to an optically transparent fusion product of inorganic materials that has cooled to a rigid state without crystallizing
Glass
Each sphere represents an atom, ion, or molecule and is called a []
lattice point
Covalent bond
covalent
Ar, CO2, I2, H2O, C12H22O11, (sucrose)
molecular
the manner in which ions, atoms, or molecules are spatially arranged
crystal structure
In a sense, the structure of [] is the simplest because every lattice point in a crystal is occupied by an atom of the same metal.
[] are generally body-centered cubic, face-centered cubic, or hexagonal close-packed. Consequently, [] elements are usually very dense.
metallic crystals
metallic
[], such as glass, lack a regular three-dimensional arrangement of atoms.
Amorphous solids
atoms are held together in an extensive three-dimensional network entirely by [] bonds.
Covalent Crystals
In the [], there are spheres at the center of each of the six faces of the cube, in addition to the eight corner spheres.
face-centered cubic cell
seven basic unit cell:
simple cubic
tetragonal
orthorhombhic
rhombohedral
monoclinic
triclinic
hexagonal
A [] arrangement differs from a simple cube in that the second layer of spheres fits into the depressions of the first layer and the third layer into the depressions of the second layer. The coordination number of each sphere in this structure is 8 (each
sphere is in contact with four spheres in the layer above and four spheres in the
layer below).
body-centered cubic
Ice is a [] solid, which possesses rigid and long-range order; its atoms, molecules, or ions occupy specific positions
crystalline
crystal structure =
lattice + basis
They can be [], with no regular pattern among the particles
amorphous
have a definite shape and volume. .
Solids
the most efficient arrangement
of spheres
Closest packing
Soft, low melting point, poor conductor of heat and electricity
molecular
the basic repeating structural unit of a crystalline solid.
unit cell
Solids are most stable in crystalline form. However, if a solid is formed rapidly (for
example, when a liquid is cooled quickly), its atoms or molecules do not have time
to align themselves and may become locked in positions other than those of a regular crystal. The resulting solid is said to be []
amorphous
C (diamond),†SiO2 (quartz)
covalent
[] in which the particles repeat at regular intervals within a crystalline lattice
crystalline
[] solids such as glass lack a well-defined arrangement and long-range molecular order.
Amorphous
an atom or group of atoms attached to every lattice points
basis
Hard, high melting point, poor conductor of heat and electricity
covalent
Hard, brittle, high melting point, poor conductor of heat and electricity
ionic
Soft to hard, low to high melting point,
good conductor of heat and electricity
metallic
a 3d network of imaginary lines connecting in space
lattice
All metallic elements; for example, Na, Mg, Fe, Cu
metallic
NaCl, LiF, MgO, CaCO3
ionic
Electrostatic attraction
ionic
The basic, repeating unit in the array of spheres is called a []
simple cubic cell (scc)
the number of atoms (or ions) surrounding an atom (or ion) in a crystal lattice.
coordination number
Metallic bond
metallic
dispersion, dipole-dipole, hbond
molecular
