Question

What type of crystalline solid is a diamond?

Answer 1

Diamond is a compound that is purely made up of carbon atoms. So, is a non-metal as it is made up of carbon atoms only. Since the carbon atom is a tetravalent atom, it can form four covalent bonds.

Complete answer:
Many elements are not found in one form, instead, they are found in many forms which are known as the allotrope forms. Some of the elements that form allotropes are carbon, sulfur, phosphorus, etc.
So, the given compound is diamond, and diamond is a compound that is purely made up of carbon atoms. So, it is non-metal as it is made up of carbon atoms only and it is an allotrope of a carbon atom.
As we know that the carbon atom is tetravalent, and it can form four covalent bonds, so in the crystal structure of diamond, each carbon atom is attached with four carbon atom by covalent bonds and each of these four carbon atoms are further attached through four carbon atoms, and all these are formed in a tetrahedral structure.
There is no molecular boundary in the structure of diamond which makes a compact and dense structure due to which the melting point of the diamond is immensely high because it is very hard to break the bonds of the carbon atom in a diamond.

Note:
There are other allotropes of carbon atoms like graphite, fullerenes, etc as graphite is the only allotrope of a carbon atom that has the ability to conduct electricity but diamond cannot electricity.