The following pictures show the electron population of the bands of MO energy levels for four different materials.
-Which of these materials has an electrical conductivity that increases with an increase in temperature?
A)materials (1)and (2)
B)materials (1)and (4)
C)materials (2)and (3)
D)materials (3)and (4)

Question

The following pictures show the electron population of the bands of MO energy levels for four different materials. 
-Which of these materials has an electrical conductivity that increases with an increase in temperature?
A)materials (1)and (2) 
B)materials (1)and (4) 
C)materials (2)and (3) 
D)materials (3)and (4)

Quizplus · Accepted Answer

Materials (2) and (3), typically semiconductors and insulators, have electrical conductivity that increases with temperature, as thermal energy helps their electrons jump into the conduction band, enhancing conductivity.

The Following Pictures Show the Electron Population of the Bands