New equations, which have analytical solutions, for lattice and electronic heat capacities, entropies and enthalpies at constant volume and constant pressure were derived by using kinetic theory, Kirchhoff and Stefan-Boltzmann laws and Wien radiation density equation. These equations were applied to the experimental constant volume heat capacity data of copper. The temperature Theta(v) corresponding to 3R/2 was found to be 78.4 K for copper. Copper shows the dimensionality crossover from 3 to 2 at about 80 K. The Theta(v)(T) is proportional to Debye temperature. The relationship between dimension and Ev was given. Temperature dependence of Debye temperature and non-monotonic behavior were discussed. The heat capacity and entropy values, predicted by the proposed models were compared with the values predicted by the Debye models. The results have shown that the proposed models fit the data better than the Debye models. Enthalpy equations derived in this study were compared with the polynomial model and a good fitting was obtained. The equation for the photon absorption equilibrium constant of copper was derived.