What type of colloid is the soap lather?

The colour of the sky is due to

What happens when an electric field is applied to a colloidal solution?

On which of the following properties does coagulating power of an ion depend?

Flocculation value of $BaCl_2$ is much less than that of $KCl$ for sol $A$ and flocculation value of $Na_2SO_4$ is much less than that of $NaBr$ for sol $B.$ The correct statement among the following is

Consider the following statements related to colloids.
$(I)$ Lyophobic colloids are not formed by simple mixing of dispersed phase and dispersion medium.
$(II)$ For emulsions,both the dispersed phase and the dispersion medium are liquid.
$(III)$ Micelles are produced by dissolving a surfactant in any solvent at any temperature.
$(IV)$ Tyndall effect can be observed from a colloidal solution with dispersed phase having the same refractive index as that of the dispersion medium.
The option with the correct set of statements is