Question

How does conductivity vary with temperature?

Answer 1

Hint : We know that when temperature is increased in case of a semiconductor the free electron gets more energy to cross the energy gap to the conduction band from the valence band. The substance that dissociates into ions in aqueous medium is known as an electrolyte. These ions are the reason for the conductivity of such solutions.

Complete Step By Step Answer:
When temperature is increased the electrons get more energy. The conductivity of a material depends on the number of charged electrons. The ability of a species to carry charge and hence conduct electricity by the movement of the charge in the provided medium is conductivity. The big difference between the two materials is the band gap of the semiconductor. Electrons in the semiconductor that do not have sufficient energy cannot contribute to the conductivity. Therefore, increasing the energy of the electrons, increases the number of electrons or holes charge carriers that can contribute to the conductivity, thereby drastically lowering the resistance. This effect does not occur in metals.
Also, we know that metals are good conductors of electricity due to the presence of free electrons. However, when we increase the temperature the vibrational motion of electrons increases and thus causes unwanted collisions which results in the increase of resistance in metals. Therefore, the mobility of electrons decreases and causes decrease in conductivity When the temperature of a solution increases, the mobility of the ions in the solution of metals increases; hence, conductivity increases.

Note :
Remember that the conductivity of metals is due to flow of electrons and that of electrolytic conductors is due to ions. The electrolytes are divided into two groups depending on their strength namely strong and weak. There are factors other than temperature that affect the conductivity of an electrolyte.