This chapter has not been finished. I have not been able to look at it for a year, and I will presumably not be able to work much or any on it in the foreseeable future either. Since I think some parts of it are already of interest, like the figures, I am posting it as is. The reader beware, much of it has been poorly proofread, if at all. The figures should be fine.
So far, the focus in this book has been mostly on electrons. That is normal because electrons are important like nothing else for the physical properties of matter. Atomic nuclei appear in the story only as massive anchors for the electrons, holding onto them with their electric charge. But then there is nuclear energy. Here the nuclei call the shots. They are discussed in this chapter.
The theory of nuclear structure is much less advanced than that of the electronic structure of atoms. Unlike the electromagnetic forces, the nuclear forces are very poorly understood. Examining them with well-understood electromagnetic probes is limited since nuclear forces are extremely strong, resisting manipulation. Accurate direct measurement of quantities of interest is usually not possible.
Physicists responded to that with a tidal wave of ingenious experiments, usually leveraging one accepted fact to deduce the next one (and at the same time check the old one). This chapter explains some important approximate quantum models that have been developed that way, ones that work very well to explain that enormous mountain of data.