Liquids and Solids

Question 1

Intermolecular Forces (IMFs)

Answer 1

Noncovalent attractive force between atoms, molecules, and/or ions

Question 2

Van der Waals Forces

Answer 2

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

Question 3

Dispersion Force (London Dispersion Force)

Answer 3

Attraction between two rapidly fluctuating, temporary dipoles; significant only when particles are very close together

Question 4

Instantaneous Dipole

Answer 4

Temporary dipole that occurs for a brief moment in time when the electrons of an atom or molecule are distributed asymmetrically

Question 5

Induced Dipole

Answer 5

Temporary dipole formed when the electrons of an atom or molecule are distorted by the instantaneous dipole of a neighboring atom or molecule

Question 6

Polarizability

Answer 6

Measure of the ability of a charge to distort a molecule’s charge distribution (electron cloud)

Question 7

Dipole-Dipole Attraction

Answer 7

Intermolecular attraction between two permanent dipoles

Question 8

Hydrogen Bonding

Answer 8

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

Question 9

Viscosity

Answer 9

Measure of a liquid’s resistance to flow

Question 10

Cohesive Forces

Answer 10

Force of attraction between identical molecules

Question 11

Surface Tension

Answer 11

Energy required to increase the area, or length, of a liquid surface by a given amount

Question 12

Adhesive Forces

Answer 12

Force of attraction between molecules of different chemical identities

Question 13

Capillary Action

Answer 13

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

Question 14

Condensation

Answer 14

Change from a gaseous to a liquid state

Question 15

Vaporization

Answer 15

Change from a liquid state to a gaseous state

Question 16

Dynamic Equilibrium

Answer 16

State of a system in which reciprocal processes are occurring at equal rates

Question 17

Vapor Pressure (Equilibrium Vapor Pressure)

Answer 17

Pressure exerted by a vapor in equilibrium with a solid or a liquid at a given temperature

Question 18

Boiling Point

Answer 18

Temperature at which the vapor pressure of a liquid equals the pressure of the gas above it

Question 19

Normal Boiling Point

Answer 19

Temperature at which a liquid’s vapor pressure equals 1 atm (760 torr)

Question 20

Clausius-Clapeyron Equation

Answer 20

Mathematical relationship between the temperature, vapor pressure, and enthalpy of vaporization for a substance

Question 21

Melting

Answer 21

Change from a solid state to a liquid state

Question 22

Freezing

Answer 22

Change from a liquid state to a solid state

Question 23

Melting Point

Answer 23

Temperature at which the solid and liquid phases of a substance are in equilibrium; see also “Freezing Point”

Question 24

Freezing Point

Answer 24

Temperature at which the solid and liquid phases of a substance are in equilibrium; see also “Melting Point”

Question 25

Sublimation

Answer 25

Change from solid state directly to gaseous state

Question 26

Deposition

Answer 26

Change from a gaseous state directly to a solid state

Question 27

Phase Diagram

Answer 27

Pressure-temperature graph summarizing conditions under which the phases of a substance can exist

Question 28

Triple Point

Answer 28

Temperature and pressure at which the vapor, liquid, and solid phases of a substance are in equilibrium

Question 29

Supercritical Fluid

Answer 29

Substance at a temperature and pressure higher than its critical point; exhibits properties intermediate between those of gaseous and liquid states

Question 30

Critical Point

Answer 30

Temperature and pressure above which a gas cannot be condensed into a liquid

Question 31

Crystalline Solid

Answer 31

Solid in which the particles are arranged in a definite repeating pattern

Question 32

Amorphous Solids (Noncrystalline Solid)

Answer 32

Solid in which the particles lack an ordered internal structure

Question 33

Ionic Solids

Answer 33

Solid composed of positive and negative ions held together by strong electrostatic attractions

Question 34

Metallic Solids

Answer 34

Solid composed of metal atoms

Question 35

Covalent Network Solids

Answer 35

Solids whose particles are held together by covalent bonds

Question 36

Molecular Solids

Answer 36

Solid composed of neutral molecules held together by intermolecular forces of attraction

Question 37

Vacancies

Answer 37

Defect that occurs when a position that should contain an atom or ion is vacant

Question 38

Interstitial Sites

Answer 38

Spaces between the regular particle positions in any array of atoms or ions

Question 39

Unit Cell

Answer 39

Smallest portion of a space lattice that is repeated in three dimensions to form the entire lattice

Question 40

Simple Cubic Structure

Answer 40

Crystalline structure with a cubic unit cell with lattice points only at the corners

Question 41

Simple Cubic Unit Cell (Primitive Cubic Unit Cell)

Answer 41

Unit cell in the simple cubic structure

Question 42

Coordination Number

Answer 42

Number of atoms closest to any given atom in a crystal or to the central metal atom in a complex

Question 43

Body-Centered Cubic Unit Cell

Answer 43

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

Question 44

Face-Centered Cubic Unit Cell

Answer 44

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

Question 45

Body-Centered Cubic (BCC) Solid

Answer 45

Crystalline structure that has a cubic unit cell with lattice points at the corners and in the center of the cell

Question 46

Isomorphous

Answer 46

Possessing the same crystalline structure

Question 47

Face-Centered Cubic (FCC) Solid

Answer 47

Crystalline structure consisting of a cubit unit cell with lattice points on the corners and in the center of each face

Question 48

Cubic Closest Packing (CCP)

Answer 48

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)

Question 49

Hexagonal Closest Packing (HCP)

Answer 49

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)

Question 50

Hole (Interstice)

Answer 50

Space between atoms within a crystal

Question 51

Tetrahedral Hole

Answer 51

Tetrahedral space formed by four atoms or ions in a crystal

Question 52

Octahedral Hole

Answer 52

Open space in a crystal at the center of six particles located at the corners of an octahedron

Question 53

Space Lattice

Answer 53

All points within a crystal that have identical environments

Question 54

X-ray Crystallography

Answer 54

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

Question 55

Diffraction

Answer 55

Redirection of electromagnetic radiation that occurs when it encounters a physical barrier of appropriate dimensions

Question 56

Bragg Equation

Answer 56

Equation that relates the angles at which X-rays are diffracted by the atoms within a crystal