Looking at the band of stability, my first intuition is to conclude (erroneously) that there is a stable isotope of every element that lies close to the belt of stability. Why is this false? (For example, Uranium has no stable isotopes.) Or in particular, why are some number of protons inherently unstable in the nucleus?
Again, based purely on my poor intuition, I would assume that some number of neutrons could be arranged with that number of protons to create stability but that is not true in all cases. Why are these numbers of protons (e.g. 92 for Uranium) unstable?