Question

The scattering of light by colloidal particles present in a colloidal solution is called ……...?

Answer 1

Hint: Scattering of light means deviation of light rays from its straight path when an obstacle is encountered. In the colloidal solution, colloids behave as an obstacle. Scattering of light gives rise to many optical phenomena like the Tyndall effect, the blue color of the sky, etc.

Complete answer:
A mixture of substance in which one substance which is microscopically dispersed insoluble particles is suspended throughout another substance is called a Colloid. A diameter of approximately one nanometer to one micrometer is the size of the dispersed particle. In colloidal, the scattering of solution will always be dependent on the size, shape, and nature of the colloidal particle.
The scattering of light by colloidal particles present in a colloidal solution that makes the entering light visible is called the Tyndall effect. Milk is an example of colloid. This means if the light passes through milk, it will be visible but when the light passes through water it will not be visible.
It applies to colloidal mixtures and fine suspensions. For example, to determine the size and density of particles in aerosols and other colloidal matter in nephelometers, the Tyndall effect is used.
It is named after the physicist John Tyndall, who first studied the phenomenon.
Hence, the correct answer is the Tyndall effect.

Note:
Rayleigh's scattering of light means a change in the direction of light.
Rayleigh scattering of light takes place when the size of the scattering particle is very small as compared to the wavelength of the light.
Rayleigh’s scattering law states that the intensity of light corresponding to a wavelength in the scattered light varies inversely as the fourth power of the wavelength.
 For dispersion of particles to qualify for the Rayleigh scattering law, the particle size needs to be below roughly 40 nanometers.
Tyndall scattering is much more intense due to the bigger size of particles involved.