Question

Diamond is a bad conductor. Graphite is a good conductor.

• A. If both assertion and reason are true and reason is a correct explanation of the assertion
• B. If both the assertion and reason are true but the reason is not a correct explanation of the assertion
• C. If the assertion is true but the reason is false
• D. If both the assertion and reason are false

Answer 1

Answer: (B)

If both the assertion and reason are true but the reason is not a correct explanation of the assertion

Answer 2

In diamond, each carbon atom is in $sp ^{3}$ hybridised state and linked to four other carbon atoms tetraherally by covalent bonds. Since there is no mobile electron present, diamond is a bad conductor of heat and electricity. In graphite each carbon atom is in $sp ^{2}$ hybridised state and is linked to three other carbon atoms in a hexagonal planar structure. The $\pi$ -electrons are free to move throughout the entire layers, therefore graphite is a good conductor of heat and electricity.