Properties of Matter & Kinetic Molecular Theory

Vocabulary flashcards covering key terms related to the properties of solids, liquids, gases, and the kinetic molecular theory as discussed in the lecture notes.

Solid

State of matter with fixed volume, definite shape, least intermolecular space, strong intermolecular forces, very slow vibrating particles, non-fluid, incompressible, and non-diffusible.

Liquid

State of matter with fixed volume but no definite shape (takes container’s shape), less intermolecular space than gases, weak intermolecular forces, moderately fast particles that slide past each other, fluid, slightly compressible, and slightly diffusible.

Gas

State of matter with no fixed volume or shape (fills available space), maximum intermolecular space, very weak intermolecular forces, very fast randomly moving particles, fluid, easily compressible, and highly diffusible.

Intermolecular Space

The distance between particles; least in solids, greater in liquids, and greatest in gases.

Intermolecular Forces of Attraction

Attractive forces between particles; strongest in solids, weaker in liquids, and weakest in gases.

Compressibility

Ability of a substance to decrease in volume under pressure; negligible in solids, slight in liquids, and high in gases.

Fluidity

Capability to flow; absent in solids, present in liquids and gases.

Diffusion

Spontaneous mixing of particles; essentially none in solids, slight in liquids, and rapid in gases.

Kinetic Molecular Theory (KMT)

Model stating that matter is composed of tiny particles in constant motion and explains behavior of solids, liquids, and gases.

Kinetic Energy

Energy of motion possessed by particles; increases with temperature and determines particle speed.

Temperature (in KMT context)

Measure directly related to the average kinetic energy of particles in a substance.

Postulates of KMT

Key ideas: particles are always moving; kinetic energy depends on temperature; there is space between particles; attractive forces exist and grow stronger as particles get closer; phase changes occur when temperature changes sufficiently.

Phase Change

Transition between states of matter (e.g., melting, freezing) occurring when temperature alters particle kinetic energy enough to overcome or reinforce intermolecular forces.

Particle Motion in Solids

Very slow vibration about fixed positions due to strong intermolecular forces.

Particle Motion in Liquids

Moderately fast movement; particles slide past one another due to weaker intermolecular forces.

Particle Motion in Gases

Very fast, random motion in all directions because of minimal intermolecular forces.

Volume vs. Shape of States

Solids and liquids have fixed volume; solids keep definite shape while liquids and gases take container’s shape; gases have neither fixed volume nor shape.