(a) What is the probability of an electron state being filled if it is located at the Fermi level?

(b) If the probability that a state is filled at the conduction band edge (Ec) is precisely equal to the probability that a state is empty at the valence band edge (Ev), where is the Fermi level located?

(c) The Maxwell-Boltzmann distribution is often used to approximate the Fermi-Dirac distribution function. On the same set of axes, sketch both distributions as a function of (E- Ef)/kT. Consider only positive values of E- Ef. For what range of (E- Ef)/kT is the Maxwell- Boltzmann approximation accurate to within 10%?