Question

Why is the Tyndall effect shown by colloidal particles? State four instances of observing the Tyndall effect?

Answer 1

When a beam of light is passed through the colloidal solution its path becomes clearly visible and appears as blue light. It is due to scattering of light by the colloidal particles. This is known as Tyndall effect.

Complete answer:
The Tyndall effect is the scattering of light as a light beam passes through a colloid. The individual suspension particles scatter and reflect light, making the beam visible. The amount of scattering depends on the frequency of the light and the density of the particles. It is caused by reflection of the incident radiation from the surfaces of the particles, reflection from the interior walls of the particles, and refraction and diffraction of the radiation as it passes through the particles. Other eponyms include Tyndall beam (the light scattered by colloidal particles).
It is shown by colloidal particles because the colloidal particle size is roughly equal to the wavelength of the light.
Four instances of Tyndall effect as follows:
The visible beam of headlights in fog is caused by the Tyndall effect. The water droplets scatter the light, making the headlight beams visible. The Tyndall effect is used in commercials and settings to determine the particle size of aerosols. It can be observed when light passes through the canopy in the forest. It is the reason for the blue colour of the sky.

Note:
The scattering of light by particles in its path is called Tyndall effect. The tiny dust particles present in the air of the room scatter the beam of light all around the room. Thus, scattering of light makes the particles visible. Tyndall effect can also be observed when sunlight passes through a canopy of a dense forest.