I feel dumb that I can't figure this out. I'm sure its something simple that I'm just not seeing, but its really frustrating. 1. The problem statement, all variables and given/known data How many electrons (in percent of the total number of electrons per mole) lie KbT (ev) below the Fermi energy? Take Ef=5eV and T=300K 2. Relevant equations Not quite sure, since the Fermi function did not work. 3. The attempt at a solution I tried using the Fermi function and end up with values around 30%. The answer (from the back of the book) is [tex]\Delta[/tex]N/Ntot=.566% Any ideas ? Thanks!