For the case of conduction electrons in a typical metal at T = 300 K (i.e. approximately room temperature), the system is far from the classical regime because R ¯ ¯ ≈ ≈ λ λ ¯ ¯ / 25 . This is due to the small mass of the electron and the high concentration (i.e. small R ¯ ¯ ) of conduction electrons in the metal. Thus Fermi–Dirac statistics is needed for conduction electrons in a typical metal.