States of Matter and the Kinetic Molecular Theory

Question 1

Define diffusion

Answer 1

The movement of atoms or molecules from an area of higher concentration to an area of lower concentration

Question 2

Define boiling point

Answer 2

The temperature of a liquid at which its vapour pressure equals the external (atmospheric) pressure

Question 3

Define Melting point

Answer 3

The temperature at which a solid, given sufficient heat, becomes a liquid

Question 4

Define Freezing point

Answer 4

The temperature at which a liquid changes to a solid by the removal of heat

Question 5

Define melting

Answer 5

The process during which a solid changes to a liquid by the application of heat

Question 6

Define Evaporation

Answer 6

The change of a liquid into a vapour at any temperature below the boiling point. (Note: Evaporation takes place at the surface of a liquid where the molecules with the highest kinetic energy are able to escape. When this happens, the average kinetic energy of the liquid is lowered, and its temperature decreases.

Question 7

Define freezing

Answer 7

The process during which a liquid changes to a solid by the removal of heat

Question 8

Define Sublimation

Answer 8

The process during which a solid changes directly into a gas without passing through an intermediate liquid phase.

Question 9

Define condensation

Answer 9

The process during which a gas or vapour changes to a liquid, either by cooling or by being subjected to increased pressure

Question 10

Describe a solid, a liquid, and a gas according to the Kinetic Molecular Theory in terms of articles of matter.

Answer 10

According to the Kinetic Molecular Theory:
o Matter consists of small particles
o The particles are in constant motion
o There are forces of attraction between the particles
o Particles collide (with the sides of the container and each other) and exert pressure
o The temperature of a substance is a measure of the average kinetic energy of the
particles
o A phase change may occur when the energy of particles changes
of matter. According to the Kinetic Molecular Theory:
o Matter consists of small particles
o The particles are in constant motion
o There are forces of attraction between the particles
o Particles collide (with the sides of the container and each other) and exert pressure
o The temperature of a substance is a measure of the average kinetic energy of the
particles
o A phase change may occur when the energy of particles changes