The electrical conductivity of a metal decreases with rise in temperature while that of semi-conductor increases. Justify.

Explanation

In case of metal , with increase in temperature, the kernels starts vibrating and therefore, they offer resistance to the flow of electrons. Hence, conductivity of metals decreases with rise in temperature. On the other hand, in case of semi-conductors, the conductivity is due to the presence of impurities and defects. As the number of defects (such as holes) increases with rise in temperature, the conductivity increases.