This process involves dispersion as well as condensation. It is used to prepare sols of metals such as gold, silver, platinum etc.
(i) In this method, electric arc is struck between electrodes of the metal immersed in the dispersion medium contianing a little alkali.
(ii) The intense heat produced vaporizes the metal which then condenses to form particles of colloidal size. The colloidal particles formed adsorb charges from the solution and get stabilized.
