General Chemistry 1 — The Particulate Nature of Matter

A set of vocabulary flashcards defining key terms, states of matter, levels of chemistry, kinetic principles, and phase changes from STEM Topic 1.

Matter

Anything that has mass and occupies space.

Particulate Nature of Matter

The model stating that matter is composed of extremely small particles (such as atoms, molecules, or ions) that are in constant motion.

Macroscopic Level

The level of chemistry that involves properties and phenomena that can be directly observed by human senses.

Particulate Level

The submicroscopic level of chemistry that describes behavior and interactions among individual atoms, molecules, and ions.

Symbolic Level

The level of chemistry where chemists use chemical symbols, formulas (such as $H_2O$), equations, graphs, and mathematical relationships to represent matter.

Solid

A state of matter characterized by a definite shape and a definite volume, with particles packed closely together and vibrating around fixed positions.

Liquid

A state of matter with a definite volume but no definite shape, where particles remain close together but can move and slide past one another.

Gas

A state of matter with neither a definite shape nor a definite volume, where particles are widely separated and move rapidly and randomly in different directions.

Compressibility

The property of matter reflecting how much its volume decreases under pressure, which is high in gases due to the large spaces between particles.

Temperature

A measure related to the average kinetic energy of the particles within a substance.

Diffusion

The spontaneous spreading of particles from a region of higher concentration toward regions of lower concentration due to random particle motion.

Physical Change

A process that alters the state, form, or appearance of a substance without changing its chemical identity.

Melting

The state change from solid to liquid, occurring when particles gain sufficient energy to move more freely.

Freezing

The state change from liquid to solid, occurring when particles lose energy and become constrained in their movement.

Vaporization

The state change from liquid to gas, occurring when particles gain energy and become widely separated.

Condensation

The state change from gas to liquid, occurring as particles lose energy and come closer together.

Sublimation

The direct phase transition of a substance from a solid to a gas without passing through the liquid state.

Deposition

The direct phase transition of a substance from a gas to a solid without passing through the liquid state.