(b) write down all the quantum numbers for the 1sa and the 2pzß state of the h atom. (c) for the h atom, the operators a, 12, and l for their eigenfunctions. commute. explain what this mean (d) write down the wavefunction for the 1sa state in product form

Consider an insulating crystal, made up of layers of atoms. what form would you expect the temperature dependence of the phonon heat capacity to approach at extremely low temperatures if the interlayer coupling is i)very strong (rigid coupling), and ii) very weak. explain.