Question

Defenitions of
(i)Scattering of light
(ii) Tyndall effect
by the term "colloidal particles" in the definition of tyndall effect, what do we mean? Does it include particles such as air molecules, water droplets, dust particles, or just the colloidal particles found in colloids?

Answer 1

i). Scattering of light.
Scattering is the phenomenon by which a beam of light is redirected in many different directions when it interacts with a particle of matter. When sunlight strikes molecules in our atmosphere, the light is redirected in many directions. The blue light is scattered more than the red light causing the sky to be blue.

ii). Tyndal effect.
The earth’s atmosphere is a heterogeneous mixture of minute particles. These particles include smoke, tiny water droplets, suspended particles of dust and molecules of air. When a beam of light strikes such fine particles, the path of the beam becomes visible. The light reaches us, after being reflected diffusely by these particles. The phenomenon of scattering of light by the colloidal particles is called Tyndall effect.


Yes Colloidal particles include all the fine particles of small size.
It refers to items of small size that are floating in a medium of one of three substances: a solid, a liquid, or a gas. Colloidal particles can be suspended in a substance just like their own or a different substance with the exception of gases. Gas particles will not suspend in another gas.