Kinetic Molecular Theory, States of Matter and Phase Changes

Flashcards for vocabulary review based on lecture notes about Kinetic Molecular Theory, States of Matter and Phase Changes.

Kinetic Energy

Energy due to motion.

Kinetic Molecular Theory

Describes the behavior of matter in terms of particles in motion.

Elastic Collision

One in which there is no net loss of kinetic energy.

Diffusion

The spontaneous spreading of a gas to occupy a space.

Effusion

Process by which gas particles under pressure pass through a tiny opening.

Surface Tension

An attraction force that tends to pull the molecules in a liquid's surface together, forming a sort of skin.

Capillary Action

The attraction of a surface of a liquid to the surface of a solid.

Vaporization

Process in which a liquid or solid changes into a gas.

Evaporation

Process in which molecules leave the surface of a nonboiling liquid.

Crystals

Substances in which the particles are arranged in an orderly, repeating, geometric pattern.

Amorphous

A solid in which the particles are arranged randomly.

Unit Cell

Is the smallest arrangement of atoms in a crystal lattice that has the same symmetry as the whole crystal.

Allotrope

An element that exists in different forms at the same state—solid, liquid, or gas.

Equilibrium vapor pressure (evp)

The pressure exerted by a vapor in equilibrium with its liquid at a given temperature.

Volatile Liquids

Liquids that evaporate readily; they have relatively weak forces of attraction between their particles.

Nonvolatile Liquids

Liquids that do not evaporate readily; they have relatively strong attractive forces between their particles.

Boiling

The conversion of a liquid to a vapor within the liquid as well as at its surface.

Boiling Point

The temperature at which the e.v.p. of the liquid is equal to the atmospheric pressure.

Sublimation

The process by which a solid changes directly to a gas without first becoming a liquid.

Freezing Point

The temperature at which a liquid is converted into a crystalline solid.

Condensation

The process by which a gas or a vapor becomes a liquid.

Deposition

The process by which a substance changes from a gas or vapor to a solid without first becoming a liquid.

Phase Diagram

A graph which indicates the conditions under which gas, liquid, and solid phases of a substance exist.

Triple Point

The single temperature & pressure condition at which a substance can exist in all three phases at the same time.

Critical temperature (tc)

The temperature above which the substance cannot exist in the liquid state.

Critical pressure (Pc)

The lowest pressure at which the substance can exist as a liquid at the critical temperature.