Suppose the electron had a very small intrinsic electric dipole moment analogous to the spin-magnetic moment (that is, μ_el proportional to σ). Treating the hypothetical -μ_el. E interaction as a small perturbation, discuss qualitatively how the energy levels of the Na atom (Z = 11) would be altered in the absence of any external electromagnetic field. Are the level shifts first order or second order? Indicate explicitly which states get mixed with each other. Obtain an expre ssion for the energy shift of the lowest level that is affected by the perturbation. Assume throughout that only the valence electron is subjected to the hypothetical interaction.