Gases, Liquids, and Solids: Phase Changes and Intermolecular Forces

Comprehensive vocabulary flashcards covering intermolecular forces, properties of liquids and solids, state transitions, and foundational climate science concepts from Chapter 8.

Intermolecular forces

The attractive and repulsive forces that occur between molecules, varying in strength from dispersion forces to hydrogen bonds.

Intra-molecular forces

The forces within molecules that hold atoms together in a chemical bond.

van der Waals forces

The collective name for attractive and repulsive forces between molecules, usually weaker than chemical bonding forces.

Dispersion forces

Brief attractions between molecules due to momentary charges caused by the random movement of electrons; also known as London dispersion forces.

Dipole-dipole force

The net electrostatic attraction that occurs between the opposite poles of polar molecules.

Hydrogen bond

The strongest intermolecular force, formed between a hydrogen atom with a partial positive charge and a small, highly electronegative atom like nitrogen, oxygen, or fluorine.

Viscosity

A measure of a liquid's resistance to flow, determined by the ease with which molecules can move past one another.

Surface tension

The property of a liquid that allows its surface to behave like an elastic skin due to inward-pulling intermolecular forces.

Surfactant

A substance that reduces surface tension, giving products like laundry detergent their cleaning ability.

Crystalline solid

A solid in which the atoms or molecules are arranged in highly regular, repeating patterns, such as salt or diamond.

Molecular solid

A type of crystalline solid where separate molecules are held together in a rigid structure by intermolecular forces.

Covalent network solid

A solid structure in which atoms are joined by covalent bonds in a continuous network, such as graphite or quartz.

Amorphous solid

A solid in which molecules are arranged in a random fashion without a particular order; also referred to as supercooled liquids.

Vaporization

The process by which a liquid changes into a gas, often used broadly to include evaporation and boiling.

Condensation

The process by which a gas or vapor changes into a liquid.

Sublimation

A state transition where a solid changes directly into a gas without passing through the liquid phase.

Deposition

The process where a gas changes directly into a solid, the reverse of sublimation.

Evaporation

The process of molecules leaving the liquid phase and entering the gas phase at the surface of a liquid below its boiling point.

Boiling point

The temperature at which the vapor pressure of a liquid equals the external atmospheric pressure.

Vapor pressure

The pressure exerted by a vapor in equilibrium with its liquid phase in a closed container.

Volatile

A description for liquids that evaporate easily because they have relatively weak intermolecular forces.

Heating curve

A graph showing the relationship between heat added and the temperature of a substance during phase transitions.

IPCC

The Intergovernmental Panel on Climate Change, a body of scientists that assesses data related to global warming and its impacts.