Consider the following about the tyndall effect.
(I) It is used to distinguish between a true and colloidal solution.
(II) It is possible only when the dispersed medium and dispersed phase differ much in their refraction indices.
(III) It is observed only when the size of colloidal particles is much smaller than the wavelength of the light used.
The correct statements are
$$ \text { Match the following. } $$
$$ \begin{array}{llll} \hline & \begin{array}{c} \text { List-I } \\ \text { (Refining method) } \end{array} & & \begin{array}{c} \text { List-II } \\ \text { (Metals to be refined) } \end{array} \\ \hline \text { (A) } & \text { Zone refining } & \text { (I) } & \text { Titanium } \\ \hline \text { (B) } & \text { Poling } & \text { (II) } & \text { Tin } \\ \hline \text { (C) } & \text { Liquation } & \text { (III) } & \text { Gallium } \\ \hline \text { (D) } & \text { Vapour phase refining } & \text { (IV) } & \text { Copper } \\ \hline \end{array} $$
The correct answer is
Assertion (A) : In group 15 elements nitrogen does not form pentahalides.
Reason (R) : Nitrogen can exhibit +5 oxidation state.
The correct option among the following is
In which of the following options, molecules are correctly arranged with respect to their bond angles.