In a pure metal the collisions that are characterized by the mean free time $ \tau $ in the expression for the resistivity are chiefly between:

Question

In a pure metal the collisions that are characterized by the mean free time  $ \tau $ in the expression for the resistivity are chiefly between:

Quizplus · Accepted Answer

The mean free time, τ, in the expression for resistivity is the average time between collisions. In a pure metal, the collisions between atoms and electrons are the most significant ones. Since the Fermi energy is the energy level that separates the occupied and unoccupied states in the metal, electrons with energy about equal to the Fermi energy will have a high probability of collision with atoms. Therefore, collisions between electrons with energy about equal to the Fermi energy and atoms are the most significant in determining the resistivity of a pure metal.

In a Pure Metal the Collisions That Are Characterized by the Mean