Properties of three states of matter

Changes in state

​Melting and Freezing

​The temperature at which a substance turns to a liquid is called the melting point (m.p.)

The temperature of liquid substance that is called down is called the freezing point (f.p.)

The melting point and freezing point of any given substance are both the same temperature.

Example the m.p. and f.p. of water is 0⁰C

Sublimation is a direct changes of state from solid to gas, or gas to solid. As with melting, this also happens at one particular temperature for each pure solid.

Example solid carbon dioxide that is often called 'dry ice'

​SUBLIMATION

Evaporation, boiling, and condensation

PURE SUBSTANCE

Pure substances have definite, sharp melting and boiling points. The presence of an impurity means that these changes will be spread over a range of temperatures in each case.

PURE SUBSTANCE

A pure substance consists of only one substance. There is nothing else in it: it has no contaminating impurities. A pure substance melts and boils at definite temperatures

​1.2 Kinetic particle theory of matter

• The pressure of a gas is produced by the atoms or molecules of the gas hitting the walls of the container. The more often the particles collide with the walls, the greater the pressure

• All matter is made up of very small particles (different substances contain different types of particle such as atom, molecules, or ions).

• Particles are moving all the time (the higher the temperature, the higher the average energy of the particle).

• The freedom of movement and the arrangement of the particles in different for the three states of matter.

​The major points of the theory are: