Define:

(a) Intermolecular force of attraction.

(b) Intermolecular space.

(c) Cohesive force

(d) Diffusion

(e) Brownian movement

(a) Particles of matter are held together by a force of attraction that exists between them. This force is known as intermolecular force of attraction.

(b) Particles of matter have space between them which is called inter-particle or intermolecular space or gap.

(c) The force of attraction between like particles or molecules is called cohesive force. It is this force which holds the molecules of a matter together.

(d) The phenomenon of intermixing of particles of one kind with another kind is called diffusion.

(e) The zig-zag motion of particles suspended in a medium is called Brownian movement. It is named after the scientist Robert Brown.