Chemistry - Chapter 12 Intermolecular Forces
Sublimation
A change directly from the solid to the gaseous state without becoming liquid
Induced Dipole
A dipole temporarily created in an otherwise nonpolar molecule, induced by neighboring charge.
Phase Diagram
A graph of the relationship between the physical state of a substance and the temperature and pressure of the substance
Viscosity
A liquid's resistance to flowing
Amorphous Solid
A solid made up of particles that are not arranged in a regular pattern.
Crystalline Solid
A solid that is made up of crystals in which particles are arranged in a regular, repeating pattern
Dipole-Dipole Forces
Attractions between oppositely charged regions of polar molecules
Ion-Dipole Forces
Attractive forces between an ion and a polar molecule
Hydrogen Bond
Bond created by the weak attraction of a slightly positive hydrogen atom to a slightly negative portion of another molecule
Condensation
Gas to a liquid.
Van der Waals Forces
Intermolecular forces of attraction, Slight attraction that develops between oppositely charged regions of nearby molecules
Vaporization
Liquid to gas
Phase
One of three forms- solid, liquid, or gas- which every substance is capable of attaining
Dynamic Equilibrium
Result of diffusion where there is continuous movement of particles but no overall change in concentration
Closet Packing
Stacking atoms in most efficient way
Phase Changes
Substances change phases by adding or subtracting energy
Dispersion Forces
Temporary dipole created when moving electrons within an element or compound concentrate themselves on one side of an atom. Usually found in nonpolar covalent compounds. Very Weak
Molar Heat of Fusion
The amount of heat absorbed by one mole of a solid substance as it melts to a liquid at a constant temperature
Molar Heat of Vaporization
The amount of heat necessary to vaporize one mole of a given liquid
Cohesion
The binding together of like molecules, often by hydrogen bonds.
Evaporation
The change of a substance from a liquid to a gas
Polarizability
The ease with which the electron distribution in the atom or molecule can be distorted, the ease with which the dipole can be induced in a non polar molecule
Molar Heat of Sublimation
The energy required to sublime 1 mole of a solid
Surface Tension
The force that acts on the surface of a liquid and that tends to minimize the area of the surface
Intermolecular Forces
The forces of attraction between molecules
Intramolecular Forces
The forces that bond atoms together within a molecule (e.g. covalent bonds)
Critical Pressure
The lowest pressure at which a substance can exist as a liquid at the critical temperature
Coordination Number
The number of ions of opposite charge surrounding each ion in a crystal
Lattice Point
The positions occupied by atoms, molecules, or ions that define the geometry of a unit cell
Unit Cell
The smallest group of particles within a crystal that retains the geometric shape of the crystal
Critical Temperature
The temperature above which a substance cannot exist in the liquid state
Triple Point
The temperature and pressure conditions at which the solid, liquid, and gaseous phases of a substance coexist at equilibrium
Boiling Point
The temperature at which a substance changes from a liquid to a gas
Melting Point
The temperature at which a substance changes from a solid to a liquid
Equilibrium Vapor Pressure
The vapor pressure measured when a dynamic equilibrium exists between condensation and evaporation
Deposition
When a gas or vapor changes directly into a solid without first changing to a liquid
Adhesion
attraction between unlike molecules
