Can a diamond conduct electricity?

Hint: Consider the concept that the flow of electricity is dependent on the presence of free electrons in a compound, and that the outermost electrons in diamond form covalent bonds, resulting in the non-availability of free electrons within diamond.

Complete answer:
Diamond is a giant covalent structure, which means that each carbon atom is covalently bonded to another carbon atom. So the four outermost electrons, which correspond to four carbon atoms, are engaged or trapped in covalent bonds, implying that no free electrons exist.
As we know, electrical conductivity is dependent on the flow of free electrons, and because diamond contains no free electrons, it is a poor conductor of electricity.
As a result, diamond is a poor electrical conductor.

Additional Information:
Due to its strong covalent bonding and low photon scattering, diamond, unlike most electrical insulators, is an excellent heat conductor. Natural diamond has a thermal conductivity of about \[2200W{\left( {m.{\text{ }}k} \right)^{ - 1}}\] , which is five times that of silver, the metal with the highest thermal conductivity.
As a result, diamonds are excellent heat conductors.

Note:
It's worth mentioning that diamond is a crystal structure with a face centred cubic (FCC) lattice. Each carbon atom forms a regular tetrahedron, a type of triangular prism, with the other four carbon atoms. The carbon atoms are found in the centre of each tetrahedron, with four in each. Diamond is said to be the hardest element on the planet due to extensive covalent bonding.