Question 1
The following pictures show the electron population of the bands of MO energy levels for four different materials.

Which of these materials is an insulator?
◦ material (1)
◦ material (2)
◦ material (3)
◦ material (4)
Question 2
The following pictures show the electron population of the bands of MO energy levels for four different materials.

Which of these materials is a metal?
◦ material (1)
◦ material (2)
◦ material (3)
◦ material (4)