Chapter summary

Chapter summary

Presentation: VPdgh

• Three states of matter are: solid, liquid and gas.

• Diffusion is the movement of particles from an area of higher concentration to an area of lower concentration.

• Brownian motion is the random movement of microscopic particles suspended in a liquid or gas, caused by collisions between these particles and the particles of the liquid or gas.

• Boiling point is the temperature at which the vapour pressure of a liquid equals the external (atmospheric) pressure.

• Melting point is the temperature at which a solid, given sufficient heat, changes its phase to become a liquid. The process is called melting.

• Freezing point is the temperature at which a liquid changes its phase to become a solid. The process is called freezing.

• Evaporation is the change of a liquid to a vapour at any temperature below the boiling point. Evaporation takes place at the surface of a liquid, where molecules with the highest kinetic energy are able to escape.

• Condensation is the process during which a gas or vapour changes to a liquid, either by cooling or by being subjected to increased pressure.

• Sublimation is the process during which a solid changes directly to a gas without passing through an intermediate liquid phase.

• The kinetic theory of matter attempts to explain the behaviour of matter in different phases.

• The kinetic theory of matter says that all matter is composed of particles which have a certain amount of energy which allows them to move at different speeds depending on the temperature (energy). There are spaces between the particles and also attractive forces between particles when they come close together.