JAMB - Physics (2003 - No. 40)

The major difference between a pure semiconductor and a pure metal is that

metals are harder than semiconductor

while resistance of metals decrease with temperature , the reverse is the case for semiconductor

the resistance of metals increases with temperature, while for semiconductors, it is the reverse

metals have forbidden gaps while semiconductors have not

Experiment shows that increase in temperature increases the resistance of a pure metal but decreases the resistance of pure semiconductor