Colloidal particles show Brownian motion.Why?

Question

Colloidal particles show Brownian motion.Why?

Answer 1

This is due to unequal bombardment of colloidal particles by the molecules of dispersion medium.

Answer 2

Brownian motion (named in honor of the botanist Robert Brown) is the random movement of particles suspended in a liquid or gas or the mathematical model used to describe such random movements, often called a particle theory.

The brownian motion in colloids occurs due to them being repelled by particles in the colloid with the same charge.