Vocabulary of Chapter 11 Flashcards
Kinetic-Molecular Theory
Describes the behavior of gases in terms of particles in motion; makes several assumptions about size, motion, and energy of gas particles
Elastic collision
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
Temperature
A measure of the average kinetic energy of the particles in a sample of matter
Diffusion
The movement of one material through another from an area of higher concentration to an area of lower concentration
Graham’s Law of effusion
States that the rate of effusion for a gas is inversely proportional to the square root of its molar mass
Pressure
Force applied per unit area
Barometor
Pascal
The SI unit of pressure; one pascal (Pa) is equal to a force of one newton per square meter
Atmosphere
The unit that is often used to report air pressure
Dalton’s Law of particle pressures
States that the total pressure of all the gases in the mixture
Dispersion forces
The weak forces resulting from temporary shifts in the density of electrons in electron clouds
Dipole-dipole forces
The attractions between oppositely charged regions of polar molecules
Hydrogen Bond
A strong dipole-dipole attraction between molecules that contain a hydrogen atom bonded to a small
Viscosity
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
Surface tension
The energy required to increase the surface area of a liquid by a given amount; results from an uneven distribution of attractive forces
Surfactants
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
Crystalline solid
A solid
Unit cell
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
Allotrope
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
Amorphous solid
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
Melting point
For a crystalline solid, the temperature at which the forces holding a crystal lattice together are broken and it becomes a liquid
Vaporization
The energy-requiring process by which a liquid changes to a gas or vapor
Evaporation
The process in which vaporization occurs only at the surface of a liquid
Vapor pressure
The pressure exerted by a vapor over a liquid
