1. The problem statement, all variables and given/known data QUESTION ADDED AS ATTACHMENT AS NEED TO SEE GRAPH. 2. Relevant equations C = (12NkBπ4/5)(T/θD)3 for T<<θD C = 3NkB for T>>θD 3. The attempt at a solution a.) So I assume the expression for the specific heat as a function of temperature that the question must want: C = (12NkBπ4/5)(T/θD)3 otherwise I thought that the specific heat wasn't dependent on temperature? The second part of this question really stumped me. I have looked though all of the books in my university library that aren't currently on loan, of which few relevant ones are left for some reason, and cant find anything that helps me extract lattice and electronic terms in the specific heat. Does any one have any Ideas? EDIT: Just found something that shows the electronic contribution: Ce = (π2/3)g(EFkb2T = γT Therefore the electronic contribution = γ = (π2/3)(3NA/2EF)kB2 Still not sure on the lattice part. \EDIT b.) I think I can do. c.) The low temperature heat capacity for KCl plotted as to demonstrate the T3 law at low temperatures. The fact that the graph of C/T vs T2 goes through the origin indicates the absence of a term linear in T. I.e there is no contribution to the energy via conduction electrons. Am I along the right lines here?