The following picture shows the electron populations of the bands of MO energy levels for elementary silicon.
-In this picture the band gap is given by letter(s)
A)a.
B)b.
C)c.
D)a and b.

Question

The following picture shows the electron populations of the bands of MO energy levels for elementary silicon. 
-In this picture the band gap is given by letter(s)
A)a. 
B)b. 
C)c. 
D)a and b.

Quizplus · Accepted Answer

The band gap is the energy difference between the top of the valence band and the bottom of the conduction band. In the picture, the valence band is labeled as "vb" and the conduction band is labeled as "cb". The area between these two bands with no electrons is indicated by the shaded region labeled "band gap". Therefore, the correct choice is B.

The Following Picture Shows the Electron Populations of the Bands