Example 10. For lithium, the Fermi energy is 4.70eV and the density of electron is 4.6 × 10²⁸/m³.

Example 10. For lithium, the Fermi energy is 4.70eV and the density of electron is 4.6 × 10²⁸/m³. Find the electron density for a metal with Fermi energy 2.35eV.