one-, two-, and three-dimensional free electron gases. consider the sommerfeld model for the free electron in 1, 2, and 3 dimensions. assume that the dimensions of the crystal are length l, area a, or volume v, respectively. take the orbital degeneracy as one (as treated in class), and the spin degeneracy as gs (two in class). show that for the various dimensions the values of kf, ef, and n(e) are: