Who introduced the concept of $Gold \ Number$?

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.

The correct option among the following is:

Which of the following statements regarding colloidal solutions is $INCORRECT$?

Which of the following is classified as a multimolecular colloid?

Sulphur sol contains