Question

Assertion (A): Diamond is a better conductor of heat than metals.

Reason (R): Diamond has no free electrons.

• 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 the correct explanation of A.
• C. A is true and R is false.
• D. A is false and R is true.

Answer 1

The correct option is B

Both A and R are true, but R is not the correct explanation of A.

Explanation of the correct answer:

Assertion:

• Diamond is a better conductor of heat than metals due to stiff chemical bonds between light carbon atoms.
• The thermal conductivity of diamond is more than 2,000 watts per meter per Kelvin, which is five times higher than the best metals such as copper.

Thus, the statement is correct.

Reason:

• Diamond is a covalent substance in which each carbon atom is joined to four other carbon atoms by strong covalent bonds.
• The carbon atoms form a regular tetrahedral network structure.
• Thus, there are no free electrons.

Thus, the statement is correct.

Therefore, Both A and R are true, but R is not the correct explanation of A.

Hence, the correct answer is (B).