Describe the Brownian motion.

Explanation

The random (Zig - Zag path ) is motion of pollen suspended in a liquid is called Brownian motion.
Brownian motion is due to the bombardment of suspended particles by molecules of the surrounding fluid . Einstein gave systematic theory of Brownian motion based on kinetic theory and he deduced the average size of molecules.
According to kinetic theory , any particle suspended in a liquid or gas is continuously bombarded from all the directions in such away that the mean free path is almost negligible . This leads to the motion of the particles in a random and zig-zag manner .
Factors affecting Brownian Motion :
(i) Brownian motion increases with increasing temperature.
(ii) It decreases with bigger particle size , high viscosity and density of the liquid (or gas) .