Liquids and Solids

Vocabulary

adhesive force

attraction between unlike molecules, such as forces between a liquid and its container

amorphous solid

solid composed of particles that are not organized into a crystalline pattern

boiling point

temperature at which a substance changes from a liquid to a gas at constant temperature and pressure

capillary action

ability of a liquid to move up a tube against other forces, such as gravity and intermolecular interactions, including surface tension and cohesion

cohesive force

attraction between the same type of molecules

condensation

phase transition from gas to liquid at a constant temperature and pressure

covalent solid

crystalline solid formed from a network of atoms joined by covalent bonds

critical pressure

minimum pressure required for condensation of a gas at its critical temperature

critical temperature

temperature above which a gas cannot become a liquid

crystalline solid

solid in which the particles repeat at regular intervals in an ordered crystalline lattice

deposition

phase transition from gas to solid

enthalpy (H)

internal energy of a system plus the work needed to displace the environment to produce the components of the system

freezing

phase transition from liquid to solid at a constant temperature and pressure

ionic solid

solid held together by electrostatic forces between positively and negatively charged ions

lattice

atoms, ions, or molecular fragments arranged in three-dimensional space

liquid

state of matter that has a definite volume but not a definite shape, consisting of particles that are close together and freely flow

melting

phase transition from solid to liquid at a constant temperature and pressure

melting point

temperature at which a substance changes from a solid to a liquid at a constant temperature and pressure

metallic solid

solid composed of atoms held together by metallic bonds

molecular solid

crystalline solid held together via van der Waals intermolecular forces

simple cubic unit cell

unit cell that forms a six-sided box with with a fourth (1/4th) of an atom, ion, or molecule located at each corner

solid

state of matter that has a definite volume and a definite shape, consisting of particles that are closely packed and move only by vibrating

sublimation

phase transition from a solid to a gas at a constant temperature and pressure

supercritical fluid

substance that has properties of both a liquid and a gas at a temperature and pressure above the critical point

surface tension

tendency of a liquid surface to acquire the smallest possible surface area and resist outside forces, such as cohesive and intermolecular forces

unit cell

simplest repeating arrangement of particles, such as atoms, molecules, or ions, within an ordered crystal

vapor pressure

pressure exerted by a vapor in equilibrium with its solid or liquid form in a closed system

vaporization

phase transition from liquid to gas at a constant temperature and pressure

X-ray crystallography

method of determining the arrangement of atoms in a crystal using X-rays