The reason for exhibiting the Tyndall effect by colloidal particles is

Given below are two statements:
Statement $I:$ In the coagulation of a negative sol,the flocculating power of the three given ions is in the order - $Al^{3+} > Ba^{2+} > Na^{+}$
Statement $II:$ In the coagulation of a positive sol,the flocculating power of the three given salts is in the order - $NaCl > Na_{2}SO_{4} > Na_{3}PO_{4}$
In the light of the above statements,choose the most appropriate answer from the options given below:

Emulsifiers are generally .......

Which of the following is true for a $Fe(OH)_3$ sol?

The correct order of coagulating power of the following ions to coagulate the positive sol is
$I. [Fe(CN)_6]^{4-}, II. Cl^{-}, III. SO_4^{2-}$

Colloidal solutions of metals like gold,silver and platinum are generally prepared by using