Which one of the following is a planar molecule?

In $XeF_2$,the hybridisation of $Xe$ is:

In which one of the following pairs do the central atoms exhibit $sp^2$ hybridization?

Describe the hybridisation in case of $PCl_{5}$. Why are the axial bonds longer as compared to equatorial bonds?

Choose the correct code of characteristics for the given order of hybrid orbitals of the same atom,$sp < sp^2 < sp^3$:
$(i)$ Electronegativity
$(ii)$ Bond angle between same hybrid orbitals
$(iii)$ Size
$(iv)$ Energy level

"Hybridisation of central atom does not always change due to back bonding". This statement is valid for which of the following compounds?
$(i)$ $CCl_3^-$ $(ii)$ $CCl_2$ $(iii)$ $(SiH_3)_2O$ $(iv)$ $N(SiH_3)_3$