Explain Tyndall effect?

Colloidal solution or sol consists of fine particles invisible to naked eyes. However, when this solution is placed against a dark background and a strong beam of light is passed through it, the light scattered by them can be observed through the ultramicroscope. The path of light can be viewed from a direction at a right angle to that of incident light. The Phenomenon of scattering of light by sol particles is called Tyndall effect. It confirms the heterogeneous nature of the colloidal solution.

What is Brownian movement ?

The Brownian movement in a colloidal system is caused by the unequal bombardment of the molecules of the dispersion medium on the colloidal particles. When more molecules strike the particles on one side, the direction of the motion of particles changes. This is only visible through ultramicroscope. In colloidal solutions, the colloidal particles are in constant zig-zag motion known as Brownian motion. This phenomenon was first observed by Sir Robert Brown in the year 1827.