Vocabulary of Chapter 11

Question 1

Kinetic-Molecular Theory

Answer 1

Describes the behavior of gases in terms of particles in motion; makes several assumptions about size, motion, and energy of gas particles

Question 2

Elastic collision

Answer 2

Collision in which no kinetic energy is lost; kinetic energy can be transferred between the colliding particles, but the total kinetic energy of the two particles remains the same

Question 3

Temperature

Answer 3

A measure of the average kinetic energy of the particles in a sample of matter

Question 4

Diffusion

Answer 4

The movement of one material through another from an area of higher concentration to an area of lower concentration

Question 5

Graham’s Law of effusion

Answer 5

States that the rate of effusion for a gas is inversely proportional to the square root of its molar mass

Question 6

Pressure

Answer 6

Force applied per unit area

Question 7

Barometor

Question 8

Pascal

Answer 8

The SI unit of pressure; one pascal (Pa) is equal to a force of one newton per square meter

Question 9

Atmosphere

Answer 9

The unit that is often used to report air pressure

Question 10

Dalton’s Law of particle pressures

Answer 10

States that the total pressure of all the gases in the mixture

Question 11

Dispersion forces

Answer 11

The weak forces resulting from temporary shifts in the density of electrons in electron clouds

Question 12

Dipole-dipole forces

Answer 12

The attractions between oppositely charged regions of polar molecules

Question 13

Hydrogen Bond

Answer 13

A strong dipole-dipole attraction between molecules that contain a hydrogen atom bonded to a small

Question 14

Viscosity

Answer 14

A measure of the resistance of a liquid to flow, which is affected by the size and shape of particles, and generally increases as the temperature decreases and as intermolecular forces increase

Question 15

Surface tension

Answer 15

The energy required to increase the surface area of a liquid by a given amount; results from an uneven distribution of attractive forces

Question 16

Surfactants

Answer 16

A compound, such as soap, that lowers the surface tension of water by disrupting hydrogen bonds between water molecules; also called a surface active agent

Question 17

Crystalline solid

Answer 17

A solid

Question 18

Unit cell

Answer 18

The smallest arrangement of atoms in a crystal lattice that has the same symmetry as the whole crystal; a small representative part of a larger whole

Question 19

Allotrope

Answer 19

One of two or more forms of an element with different structures and properties when they are in the same state - solid, liquid, or gas

Question 20

Amorphous solid

Answer 20

A solid in which particles are not arranged in a regular, repeating pattern that often is formed when molten material cools too quickly to form crystals

Question 21

Melting point

Answer 21

For a crystalline solid, the temperature at which the forces holding a crystal lattice together are broken and it becomes a liquid

Question 22

Vaporization

Answer 22

The energy-requiring process by which a liquid changes to a gas or vapor

Question 23

Evaporation

Answer 23

The process in which vaporization occurs only at the surface of a liquid

Question 24

Vapor pressure

Answer 24

The pressure exerted by a vapor over a liquid

Question 25

Boiling point

Answer 25

The temperature at which a liquid’s vapor pressure is equal to the external pr atmospheric pressure

Question 26

Freezing point

Answer 26

Temperature at which a liquid is converted into a crystalline solid

Question 27

Condensation

Question 28

Phase diagram

Question 29

Triple point