Concept:Electrical conductivity in a solid lattice requires the presence of mobile charge carriers, such as free, delocalized electrons.
Solution:- In a diamond crystal, every single carbon atom is \( \text{sp}^3 \) hybridized.
- This means all four of its valence electrons are strictly localized, participating in strong covalent sigma bonds with four neighboring carbon atoms.
- Because all electrons are tightly locked in place to form the rigid 3D tetrahedral network, there are absolutely zero free electrons available to transport electrical charge.
- Therefore, electrically, diamond is a strict non-conductor (insulator).
Why other options are incorrect:- A, C: Diamond lacks the free electrons required to be a good conductor or even a semiconductor under standard conditions (unlike its allotrope, graphite, which has delocalized pi electrons).
Quality & Fidelity Assurance:
Every question on BeambePrep is rigorously curated against the official PMDC syllabus with zero filler, zero out-of-syllabus content, and zero typos. When an authentic past paper originally contained a historical mistake or ambiguity from the examining board (such as UHS or NUMS), BeambePrep faithfully reflects the original paper while detailing the nuance and scientific consensus in the autopsy above.