Each physical state of matter possesses characteristics properties of its own. For example,


All solids show the following characteristics-

(i) Solids are rigid, and incompressible.

(ii) Solids have fixed shape and definite volume.


(iii) Solids have their melting and boiling points above room temperature.


All liquids show the following characteristics:

(i) Liquids are almost incompressible but less incompressible than solids.

(ii) Liquids have fixed volume but no fixed shape.


(iii) Liquids flow from higher to lower level.

(iv) Liquids have their melting points below room temperature and boiling points above room temperature, under normal conditions.


All gases show the following characteristics:

(i) Gases are highly compressible, i.e. gases can be compressed easily by applying pressure.


(ii) Gases have no fixed volume and shape. Gases fill the container of any size and shape completely.

(iii) Gases can diffuse into each other rapidly.

(iv) Gases have their melting and boiling points both below room temperature.