A quantity of any substance equal to its molecular weight in grams is a mole of that substance contains the same number of molecules as one mole of any other substance. This Avogadro's number and equals 6.02 x 10²³ molecules per mole. Thus = 9.03 x 10²⁸ electrons/m³ Since for tungsten the atomic and the molecular weights are the same. Therefore for tungsten E_F = 3.64 x 10^-19(η)^2/3 = 3.64 x 10^{- 19}(9.03 x 10²⁸)^2/3 E_F = 7.326 eV.