Reason (R): Due to thermal excitation of many electrons from the valence band to the conductance band, metals have high thermal conductivity.
A. Both (A. and (R) are correct and (R) is the correct explanation of(A).
B. Both (A) and (R) are correct but (R) is not the correct explanation of(A).
C. (A) is wrong but (R) is correct.
D. (A) is correct but (R) is wrong.
Answer:A
Reason (R): Due to thermal excitation of many electrons from the valence band to the conductance band, metals have high thermal conductivity.
A. Both (A. and (R) are correct and (R) is the correct explanation of(A). B. Both (A) and (R) are correct but (R) is not the correct explanation of(A). C. (A) is wrong but (R) is correct. D. (A) is correct but (R) is wrong.