Discuss the hybridisation of carbon atoms in allene `(C_(3)H_(4))` and show the `pi`-orbital overlap.

Explanation

Allene is : `{:(CH_2=C=CH_2),(I" "II" "III):}`
Carbon atoms I and III are `sp^3` hybridised while carbon II is sp hybridized. The two unhybridised orbitals of carbon II overlap sidewise with unhybridised p orbitals of carbon I and III to form `pi` bonds.