the order of repulsion between different pair of electrons is $lp\mathit{-}lp\mathit{>}lp\mathit{-}bp\mathit{>}bp\mathit{-}bp\mathit{ }\mathit{(}lp\mathit{ }\mathit{=}\mathit{ }$lone pair electrons, $\mathrm{bp} =$ bond pair electrons)

the number of lone pairs on $\mathrm{O}$ in  ${\mathrm{H}}_2\mathrm{O}$is 1 while on N in ${\mathrm{NH}}_3$ is 2.

as the number of lone pair of electrons on central atom increases, the deviation in BA form normal BA (Bond-Angle) also increases

the structures of xenon-fluorides and xenon oxyfluorides could be explained on the basis of VSEPR theory.