Question

The Tyndall effect associated with colloidal particles is due to:
A. presence of electrical charges
B. scattering of light
C. adsorption of light
D. reflection of light

Answer 1

Hint: The Tyndall effect was first discovered by the Irish physicist John Tyndall. The Tyndall effect is the phenomenon whereby the particles in a colloid scatter light beams directed at them. All colloidal solutions and some very fine suspensions exhibit this effect. As a result, it can be used to determine if a solution is a colloid.

Complete answer:
The Tyndall effect is caused due to scattering of light by the colloidal particles. The colloidal particles first absorb light and then a portion of the absorbed light is scattered from the surface of the colloidal particles. When viewed from that direction, the route becomes visible due to the maximum dispersed intensity being in a plane at right angles to the plane of incident light.
The intensity of scattered light is determined by the density of colloidal particles as well as the incident light's frequency.
Some examples of Tyndall effect are:
Milk is a colloid that contains fat and protein globules. A beam of light is scattered when it is directed at a glass of milk. This is an excellent illustration of the Tyndall effect.
The path of light becomes evident when a torch is turned on in a foggy atmosphere. The light scattering in this scenario is caused by water droplets in the fog.
Hence, the correct option is B. scattering of light

Note:
When the size of the particles causing the scattering are bigger than the wavelength of the dispersed light, Tyndall scattering occurs. It is caused by reflection of the incident radiation from the surfaces of the particles, and refraction and diffraction of the radiation as it passes through the particles, reflection from the interior walls of the particles.