Define each of the following terms:

(i) Micelles

(ii)Peptization

(iii)Desorption

(i) A micelle is an aggregate of surfactant molecules dispersed in a liquid. A micelle in aqueous solution forms an aggregate such that the hydrophilic "head" regions are in contact with the surrounding solvent and the hydrophobic tail regions are in the center of micelle.

(ii) Peptization is the process of conversion of a precipitate into a colloidal sol by shaking it with the dispersion medium in the presence of an electrolyte. The electrolyte used in this reaction is known as a peptizing agent.

(iii) Desorption is the process of removing an adsorbed substance from the surface through which it was adsorbed.