Particle/Kinetic Theory of Matter — States of Matter and Brownian Motion

Vocabulary flashcards covering key terms from the notes on matter, particle/kinetic theory, states of matter, energy content in the three states, and Brownian motion.

Matter

Anything that occupies space and has mass; matter is made up of tiny particles (molecules) held together by forces of attraction.

Molecule

The smallest unit of a substance that retains its properties; made of two or more atoms bonded together.

Intermolecular forces of attraction

Forces of attraction between molecules; strength varies by state: strongest in solids, weaker in liquids, weakest in gases.

Solids

State of matter with strong intermolecular forces, definite shape and volume; particles vibrate in fixed positions.

Liquids

State of matter with weaker intermolecular forces than solids, definite volume but no fixed shape; particles flow.

Gases

State of matter with very weak intermolecular forces; particles move freely, no fixed shape or volume.

Fluids

Substances that can flow; includes liquids and gases.

Brownian motion

Random movement of microscopic particles suspended in a fluid due to collisions with surrounding molecules.

Robert Brown

Botanist who first observed Brownian motion, supporting the particle theory of matter.

Particle theory of matter

The idea that matter is made of tiny moving particles; explains states and properties.

Kinetic theory of matter

Another name for the particle theory emphasizing the motion and energy of particles.

States of matter

The distinct forms solids, liquids, and gases in which matter can exist.

Change of state

Transition of matter between solid, liquid, and gas due to energy transfer (e.g., heating or cooling).

Energy content in the three states

Kinetic energy of particles is lowest in solids, higher in liquids, highest in gases.