Which of the following is an example of a macromolecular colloid?

Identify the dimensional nature of nanoparticles.

Given below are two statements ($S-I$ and $S-II$):
$S-I$: Scattering of light by dispersed particles of a colloidal system is known as the Tyndall effect.
$S-II$: The diameter of the dispersed particles should not be much smaller than the wavelength of the light used.
Choose the most appropriate answer from the options given below.

Assertion : Sky appears blue.
Reason : Colloidal particles of dust scatter blue light.

Detergent action of soap is due to

What happens when a lyophilic sol is added to a lyophobic sol?