Estimate the fraction of electrons excite above the Fermi level at room temperature (T=300K) for Sodium and copper? Given the Fermi energy (EF) for sodium and copper is 3.1eV and 7eV respectively.

Copper metal can be well-described by assuming that the electrons inside are free, with a den- sity ne = 8.47 × 1028 m-³. Calculate the Fermi energy EF.

Strontium crystal has a mass density of 2.64 g/cm' and a molar mass of 87.62 g/mol   Calculate Fermi energy and Fermi velocity of electrons in Sr crystal.

The Fermi energy of silver is µF = 5.51 eV. a) Calculate µ(7) of Ag at T = 400 and 4000 K. b) What is the rms speed of electrons at 0 K? What is the Fermi velocity? c) Plot the Fermi function at 0 and 4000 K in one graph and discuss the differences.