Which of the following properties of colloids is used to measure the rate of migration of sol particles?

Gold number is defined as:

Identify the method of preparation of a colloidal sol from the following.

Which one of the following is used as an eye lotion?

How are the colloidal solutions classified on the basis of physical states of the dispersed phase and dispersion medium?

The correct statement$(s)$ related to colloids is(are):
$(A)$ The process of precipitating colloidal sol by an electrolyte is called peptization.
$(B)$ Colloidal solution freezes at a higher temperature than the true solution at the same concentration.
$(C)$ Surfactants form micelles above the critical micelle concentration $(CMC)$. $CMC$ depends on temperature.
$(D)$ Micelles are macromolecular colloids.