Which of the following is an example of a hydrophobic sol?

Which of the following nanomaterials has one dimension less than $100 \ nm$?

$A$ system of cellulose dispersed in alcohol is known as a ...... .

In each of four separate beakers $(I, II, III, IV)$,$X \ mL$ of $y \ M \ Fe_2O_3 \cdot xH_2O$ colloidal solution is present. Equal volume and equal concentration of $KCl, K_4[Fe(CN)_6], K_3PO_4$ and $K_2SO_4$ were added into $I, II, III$ and $IV$ respectively. The efficiency of precipitation in these beakers follows the order:

On addition of $1 \ mL$ of $10 \%$ $NaCl$ to $10 \ mL$ gold sol in the presence of $0.038 \ g$ of starch the coagulation is just prevented. Then the value of gold number of starch is

$A$ colloidal system consisting of a gas dispersed in a solid is called a/an: