Nature of Particles - Definitions

Brownian Motion

The random, jerky movements in all directions of particles suspended in a medium.

Diffusion

The movement of particles from an area of high concentration to an area of low concentration.

Empirical

Information gathered through observation and experimentation.

Theory

An idea used to account for an observation made in a situation.

Mass

Anything that has mass and takes up space.

Melting point

The specific temperature at which a solid completely changes into a liquid when heat is added.

Boiling point

The temperature of a liquid at which the vapour pressure is squeal to the surrounding atmospheric pressure.

Freezing point

The specific temperature at which a liquid completely changes into a solid when heat is removed.

Melting

The process by which a substance changes from a solid to a liquid.

Freezing

The process by which a substance changes from a liquid to a solid.

Evaporation

The process by which a substance changes from a liquid to a gas. It only takes place at the surface of the liquid and is slower than boiling.

Condensation

The process by which a gas/vapour completely changes to a liquid when heat is removed.

Sublimation

The process by which. solid changes directly into a gas without going through an intermediate liquid state, when heat is added.