申論題

5.[20 points] There are N free electrons in a metal of volume V and the temperature is at absolute zero. It is also known that the distribution of the frce electron energy can be described by the density of the electron energy levels, where e is the (kinetio) cnergy of the frce electron and is the number of electronic energy levels (including both spins) between e and m the mass of electron, and h the Planck' s constant.