Question

The allotrope of carbon that is a good conductor of heat and electricity is:

• A. Diamond
• B. Graphite
• C. Charcoal
• D. Coal

Hint:

Remember: Diamond is the hardest allotrope of carbon, whereas graphite is the best conductor of electricity among common carbon allotropes.

Answer 1

The Correct Option is B

Concept: Graphite and diamond are both allotropes of carbon, but they possess completely different structures and properties.

Step 1: Understand the structure of graphite.
In graphite, each carbon atom is bonded to only three neighboring carbon atoms. These atoms form flat hexagonal layers. The fourth valence electron of each carbon atom remains free and becomes delocalized.

Step 2: Effect of delocalized electrons.
The free electrons can move throughout the layers. Because electric current is the movement of charged particles, these mobile electrons enable graphite to conduct electricity. The movement of these electrons also helps in transferring heat effectively.

Step 3: Compare with diamond.
In diamond, all four valence electrons are used in bonding. Therefore, no free electrons are available for conduction. Hence diamond is an electrical insulator. Therefore, the carbon allotrope that conducts heat and electricity is: \[ \boxed{\text{Graphite}} \]