Question

Assertion : Diamond is a bad conductor. 

Reason: Graphite is a good conductor.

(a) Both A and R are true and R is the correct explanation of A

(b) Both A and R are true but R is not correct explanation of A

(c) A is true but R is false

(d) A and R are false

Answer 1

Correct option (b) Both A and R are true but R is not correct explanation of A

Explanation:

In diamond, each carbon atom is in sp² hybridised state and linked to four other carbon atoms  tetrahedrally by covalent bonds. Since there is no mobile electron present, diamond is bad conductor of heat and electricity.

In graphite each carbon atom is in sp² hybridised state and is linked to three other carbon atoms in a hexagonal planar structure. The π-electrons are free to move throughout the entire layers, therefore graphite is good conductor of heat and electricity.