Q. Which allotrope of carbon is the hardest natural substance?
✅ Correct Answer: (C)
Diamond
Explanation: Diamond has a three-dimensional tetrahedral network of carbon atoms, making it the hardest known natural substance. Graphite and fullerene are much softer.
Explanation by: Sikhar Chaudhary
Diamond has a three-dimensional tetrahedral network of carbon atoms, making it the hardest known natural substance. Graphite and fullerene are much softer.