Chapter 11 Flashcards
what does crystalline mean?
a solid in which atoms, molecules, or ions are arranged in patterns with long-range, repeating order
what does amorphous mean?
a solid in which atoms or molecules do not have any long-range order
what is Coulomb’s law?
E = q1q2/r
what are intermolecular forces?
the forces between of attraction and repulsion between different molecules
what is ion-induced dipole force?
an intermolecular force between ions and a non-polar molecule
what are dispersion forces?
an intermolecular force (a type of ion-induced dipole force) exhibited by all atoms an molecules that result from fluctuations in the electron distribution
what are dipole-dipole forces?
an intermolecular force exhibited by polar molecules that result from the uneven charge distribution
what is a temporary dipole?
a permanent separation of charge; a molecule with permanent dipole always has a slightly negative charge at one end and a slightly positive charge at the other end
what is miscibility?
the ability to mix without separating into two phases
what is hydrogen bonding?
a strong type of intermolecular bonding that occurs between polar molecules that contain hydrogen atoms bonded directly to small electronegative atoms (FON)
what is a hydrogen bond ?
a strong dipole-dipole attractive force between a hydrogen bonded to FON and one of these electronegative atoms on a neighbouring molecule
what are dipole-induced dipole forces?
an intermolecular force between molecules that have a permanent dipole and an atom or molecule that is non-polar
what are ion-dipole forces?
an intermolecular force between an ion and the oppositely charged end of a polar molecule
what is surface tension?
The energy required to increase the surface area of a liquid by a unit amount: responsible for the tendency of liquids to minimize their surface, giving rise to a membrane-like surface
what is viscosity?
a measure of the resistance of a liquid to flow
what is capillary action?
the ability of a liquid to flow against gravity up a narrow tube due to adhesive and cohesive forces
what does vaporization mean?
the phase transition from liquid to gas
what is condensation?
the phase transition from gas to liquid
what does volatile mean?
tending to vaporize easily
what does nonvolatile mean?
not easily vapourized
Summarize the process of water vaporization?
- The rate of vaporization increases with increasing temperature
- The rate of vaporization increases with increasing surface area.
- The rate of vaporization increases with decreasing strength of intermolecular forces.
what is melting point?
The temperature at which the molecules of a solid have enough thermal energy to overcome intermolecular forces and become a liquid
what is melting (Fusion)?
the transition from solid to liquid
what is freezing?
the transition from liquid to solid
what is X-ray diffraction?
a powerful laboratory technique that allows for the determination of the powerful arrangement of atoms in a crystal and the measuring of the distance between them
what is Bragg’s Law ?
nλ =2d sinθ
distance between atomic layers = d = nλ/2d sinθ
what is a crystalline lattice?
the regular arrangement of atoms in a crystalline solid
what is a unit cell?
The smallest divisible unit of a crystal, that when repeated in 3D, reproduces the entire crystal lattice
what is a simple cubic?
a unit cell that consists of a cube with one atom at each corner
what is a coordinate number?
the number of molecules or ions directly bound to the metal atom in a complex ion
what is packing efficiency?
The percentage of volume of a unit cell occupied by atoms, assumed to spherical
what is the body-centred cubic?
a unit cell that consists of a cube with one atom at each corner and one atom at the centre of the cube
coordinate number = 8
what is the face-centred cubic?
a crystal structure whose unit cell consists of a cube with one atom at each corner and one atom in the centre of every face
coordinate number = 12
what is a hexagonal closet packing ?
a closet packed arrangement in which the atoms of the third layer align exactly over those in the first layer
what is cubic closet packing?
a closet packed arrangement in which the third layer of atoms is offset from the first: the same structure as the faced-centred cubic
what are molecular solids?
solids whose composite units are molecules; they generally have low melting points
what are ionic solids?
solids whose composite units are ions; generally have high melting points
what are atomic solids?
solids whose composite units are atoms, they include nonbonding atomic solids, metallic atomic solids, network covalent solids
what are nonbonding atomic solids?
atomic solids held together by dispersion forces; they have low melting points
what are metallic atomic solids?
atomic solids held together by metallic bonds; they have variable melting points
what are network covalent atomic solids?
atomic solids held together by covalent bonds; they have high melting points
what is band theory?
A model for bonding in atomic solids that comes from molecular orbital theory in which atomic orbitals combine and become delocalized over the entire crystal
what is a band gap?
an energy gap that exists between the valence band and conduction band of semiconductors and insulators
what is n-type semiconductor?
a semiconductor that employs negatively charged electrons in the condition band as the charge
what is a diode?
a device that allows the flow of electrical current in only one direction
what is a p-type semiconductor?
a semiconductor that employs positively charged “holes” in the valence band as the charge carriers
what are p-n junctions?
tiny areas in electrical circuits that have a p-type semiconductors on one side and n-type on the other
