Question

Question 7 When the conduction electrons in a metal are treated as an ideal gas of fermions, the mean number of electrons occupying a state with energy e is given by I+ (-2) (3)u (a) Define the Fermi energy [ marks] (b) Sketch n as a function of e for an electron gas: (i) at T 0 K, and to the Fermi temperature (ii) at a temperature above 0 K, but small compared Label and briefly justify each sketch [5 marks] (c) Describe the change in the variation of n with e as the temperature increases, and hence explain why conduction electrons make only a small contribution to the heat capacity of a metal at room temperature [4 marks

Answer 1

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