GEN CHEM2 Flashcards
molecules simply vibrate and rotate in place rather than move about.
Solid
the molecules are not moving in the same manner as those in liquids or gases.
Solid
generally held together by ionic or strong covalent bonding, and the attractive forces between the atoms, ions, or molecules are very strong.
Solid
have definite shapes and definite volumes and are not compressible to any extent.
solid
have a regular, highly ordered arrangement
Crystalline solids
have a random, disordered arrangement.
Amorphous solids
arranged in fixed geometric patterns or lattices.
Crystalline solids
Examples of crystalline solids
ice and sodium chloride (NaCl), copper sulfate (CuSO4), diamond, graphite, and sugar (C12H22O11).
The structures of crystalline solids are built from repeating units called
crystal lattices.
have a random orientation of particles.
Amorphous solids
Examples of amorphous solids are
glass, plastic, coal, and rubber.
They are considered super-cooled liquids where molecules are arranged in a random manner similar to the liquid state.
Amorphous solids
Crystal structure of a solid can be determined by—.This process provides information on bond lengths and angles.
x-ray diffraction
pioneered the work on X-ray crystallography and were awarded the Nobel Prize in Physics in 1915.
William Henry Bragg and William Lawrence Bragg
relatively small repeating unit that is made up of a unique arrangement of atoms and embodies the structure of the solid.
Unit cell
has an identical environment. The positions of the lattice points are defined by the lattice vectors.
Lattice points
Lattice points only at corners.
Primitive Cubic Lattice
Lattice points at corners plus one lattice point in center of unit cell.
Body-centered cubic lattice
Lattice points at corner plus one lattice point at the center of each face.
Face-centered cubic lattice
different substances that crystallize in the same lattice with the same atomic arrangements
Isomorphous
substances that crystalize in several arrangements
Polymorphous
are crystals that are the same in two dimensions but different in the third
Polytypes
are made of atoms that readily lose electrons to form positive ions (cations), but no atoms in the crystal would readily gain electrons.
Metallic crystals
cations and anions form strong electrostatic interactions that hold the crystal lattice together.
Ionic crystals
The atoms or molecules are held together by a mix of hydrogen bonding/dipole-dipole and dispersion forces, and these are the attractive forces that are broken when the crystal melts..
Molecular crystals
are made of atoms in which each atom is covalently bonded to its nearest neighbors.
Covalent network crystals
made up of layers of rings of carbon atoms.
Graphite
