Question

What is the Hybridization of the diamond?

Answer 1

We all know that diamond and graphite are allotropes of carbon which have different physical properties and the most responsible aspect for it, is hybridisation of carbon atoms. Hybridization is a process of combination or mixture of atomic orbitals to form a new one .

Complete answer:
Basically, to determine hybridisation of any atom we count the number of atoms connected to it then we count the number of lone pair and then adding these two together if its four $s{p^3}$ then if its three $s{p^2}$ then if its two $sp$ hybridised.
In case of carbon present in diamond every carbon has four bonds with other four carbon and the valency of carbon is four. Hence, the number of lone pairs present is zero. So, the total of atoms attached to one carbon atom and the lone pair around it is four.
All the carbon atoms in diamond have strong chemical bonds with the other four carbon atoms around it hence the carbon atom in diamond is $s{p^3}$ hybridised.

Note:
While talking about allotropes of carbon with diamond and graphite it has other several allotropes such as lonsdaleite, amorphous carbon and many more. Diamond is the hardest allotrope of carbon. Diamond does not undergo any chemical reaction.