The energy of second Bohr orbit of hydrogen atom is -3.4 eV . The energy of the fourth Bohr orbit of the $\mathrm{He}^{+}$ ion will be

$$ \text { Observe the following data : } $$

$$ \begin{array}{lllll} \hline \text { Ion } & Q^{a+} & X^{b+} & Y^{c+} & Z^{\alpha+} \\ \hline \text { Radius (pm) } & 53 & 66 & 40 & 100 \\ \hline \end{array} $$

$Q^{a+}, X^{b+}, Y^{c+}, Z^{d+}$ are respectively

$$ \text { Which of the following sets are correctly matched? } $$

$$ \begin{array}{llll} \hline & \text { Molecule } & \text { Hybridisation } & \text { Geometry } \\ \hline \text { I. } & \mathrm{BrF}_5 & s p^3 d^2 & \text { Square pyramidal } \\ \hline \text { II. } & \mathrm{XeF}_6 & s p^3 d^3 & \text { Distorted octahedral } \\ \hline \text { III. } & \mathrm{SF}_4 & d s p^2 & \text { Square planar } \\ \hline \text { IV. } & \mathrm{PbCl}_2 & s p & \text { Linear } \\ \hline \end{array} $$

The order of dipole moments of $\mathrm{H}_2 \mathrm{O}(A), \mathrm{CHCl}_3(B)$ and $\mathrm{NH}_3(C)$ is