Number of molecules/species from the following having one unpaired electron is ________.

$$\mathrm{O}_2, \mathrm{O}_2^{-1}, \mathrm{NO}, \mathrm{CN}^{-1}, \mathrm{O}_2^{2-}$$

The number of molecules/ion/s having trigonal bipyramidal shape is _______.

$\mathrm{PF}_5, \mathrm{BrF}_5, \mathrm{PCl}_5,\left[\mathrm{Pt} \mathrm{Cl}_4\right]^{2-}, \mathrm{BF}_3, \mathrm{Fe}(\mathrm{CO})_5$

The lowest oxidation number of an atom in a compound $\mathrm{A}_2 \mathrm{B}$ is -2 . The number of electrons in its valence shell is _______.

A diatomic molecule has a dipole moment of $$1.2 \mathrm{~D}$$. If the bond distance is $$1 \mathrm{~A}^{\circ}$$, then fractional charge on each atom is _________ $$\times 10^{-1}$$ esu.

(Given $$1 \mathrm{~D}=10^{-18}$$ esucm)