What is meant by hybridisation ? Compound `CH_(2)=C=CH_(2)` contains `sp` or `sp^(2)` hybridised carbon atoms. Will it be a planar molecule ?

Explanation

`overset((sp^(2)))(H_(2)C)=overset((sp))(C)=overset((sp^(2)))(CH_(2))`
Cantral carbon atom is `sp` hybridised and its two unhybridised p-orbitals are perpendicular to each other as shown in the figure. The p-orbital in one plane overlaps with one of the p-obitals of left terminal carbon atom and the p- orbital in other plane overlaps with p-orbital to right side terminal carbon atom. this fixes the position of two terminal carbon atoms and the hydrogen atoms attached to them in planes perpendicular to each other. this means that the pair of hydrogen atoms attached to terminal carbon atoms are present in different planes. therefore, the molecule is not planar.