JEE Main · 2023 · 08 Apr 2023 · Shift 2 · p-Block Elements

The lone pairs on xenon are found by counting the electron pairs left after bonding. In ${\mathrm{XeF}}_5^{+}$ there are five bond pairs and one lone pair, giving a square pyramidal shape. In ${\mathrm{XeO}}_3$ there are three sigma bonds and one lone pair, giving a pyramidal shape. In ${\mathrm{XeO}}_2{\mathrm{F}}_2$ there are four sigma bonds and one lone pair, giving a see-saw shape. In ${\mathrm{XeOF}}_4$ there are five sigma bonds and one lone pair, giving a square pyramidal shape. By contrast ${\mathrm{XeF}}_5^{-}$ and ${\mathrm{XeF}}_4$ each have two lone pairs and ${\mathrm{XeO}}_3{\mathrm{F}}_2$ has none. Four species carry a single lone pair on xenon.