The blue color of the sky is due to $.....$.

Which characteristic is true in respect of colloidal particles?

Coagulating value of electrolytes $AlCl_3$ and $NaCl$ for $As_2S_3$ are $0.09$ and $50.04$ respectively. The coagulating power of $AlCl_3$ is $x$ times the coagulating power of $NaCl$. The value of $x$ is $.......$.

What are emulsions? What are their different types? Give an example of each type.

Which colloidal sol is known as 'Aqua-dag'?

The gold numbers of gelatin, haemoglobin and sodium acetate are $5 \times 10^{-3}$, $5 \times 10^{-2}$ and $7 \times 10^{-1}$, respectively. The protective actions will be in the order