1. The problem statement, all variables and given/known data At what temperature T does the specific heat of the free electrons become larger than the specific heat of the lattice? Express T in terms of the Debye temperature and the electron concentration. Calculate T for copper (Debye = 343 K). 2. Relevant equations Unfortunately, I have a ton of equations but have no clue which one to use. There are different equations for low and high temperatures, so I'm not sure where to start with this problem. 3. The attempt at a solution Once I have the first part, I can solve for T for copper. I think I'm supposed to use some equations involving heat capacity and temperature, but no clue which one??? Any hints may help! My book (Kittel's intro to solid state) is not helping... Thanks!