Question

In good conductor, the gap between the valence band and the conduction band is

• A. infinite
• B. large but not infinite
• C. zero
• D. small but not zero

Hint:

In metals the valence band and conduction band overlap, so there is no gap.

Answer 1

The Correct Option is C

Step 1: Compare the options
An infinite or large gap describes an insulator.
A small non-zero gap describes a semiconductor.

Step 2: Conclusion
A good conductor has overlapping bands, so the gap is zero.

Step 3: Final check
Metals conduct without any thermal or optical excitation, which is only possible when no gap separates the bands.

Final Answer:
A good conductor has zero gap between the bands. \[ \boxed{\text{(C) }\text{zero}} \]