There's a balance of forces which results in binding energy per nucleon depending on the number of nucleons, but overall it's something like 8 MeV per nucleon,

There's a balance of forces which results in binding energy per nucleon depending on the number of nucleons, but overall it's something like 8 MeV per nucleon, so He-4 ends up with ~28.3 MeV of binding energy, while U-235 goes up to 1.8 GeV due to the sheer number of nucleons. Note the downwards slope of the binding energy per nucleon in the graph, this kinda indicates how stability goes down. There are however "magic numbers" and iirc there is a hypothesis that you get a sort of "island of stability" way into not-yet-existing super-heavy trans-uranic elements. https://upload.wikimedia.org/wikipedia/commons/thumb/5/53/Binding_energy_curve_-_common_isotopes.svg/1280px-Binding_energy_curve_-_common_isotopes.svg.png https://upload.wikimedia.org/wikipedia/commons/thumb/5/53/Bi... https://www.youtube.com/watch?v=SgM2wxELF4U https://www.youtube.com/watch?v=SgM2wxELF4U