1) [20 points] The density of copper is 8.96 g/cm³ and its atomic weight is 63.5 g/mol. a. Calculate the Fermi energy for copper in electron volts. Assume that each copper atom donates one free electron. b. What is the velocity of an electron with this energy? Is it safe to assume that electrons in copper are nonrelativistic? c. At what temperature would the characteristic thermal energy kgT be equal to the Fermi energy for copper? This temperature is known as the "Fermi temperature". As long as the actual temperature of the solid is well below the Fermi temperature, the material can be regarded as "cold" with most of its electrons in the lowest accessible state (the collective ground state for the system). In this sense, would solid copper ever be considered "hot"?