Trying to understand how the energy related to nuclear reactions. In particular why particular fusion of small nuclei release energy. So far, there seems to be two explanations which I have encountered that I understand (I'm in High School currently, so have stayed away from the large number of super scary, equation-heavy quantum mechanics ones).
One involves potential energy (and potential energy wells), and the other involves changes in mass/mass energy. I think I understand both of these separately:
During fusion of small nuclei, energy is required to overcome the coulombic repulsion between the nuclei, and get over the potential 'hump'. Once this is done, the strong interaction takes over as they fall into the well, and energy is released as potential energy is lost (due to positive work done by the strong interaction).
The other is the binding energy per nucleon explanation which essentially comes down to the fact that small nuclei have lower mass nucleons than slightly larger ones (when they're smaller than iron). So, when small nuclei smash together and form the larger one, mass is lost, this mass being converted into the kinetic energy of the products (by E=mc^2) - so that mass-energy is conserved.
My question is essentially whether these explanations can be combined into one (so is there some hidden link between them), or is one is more correct than the other, or have I just gotten something wrong (if there's a better explanation which is reasonably intuitive). I thought perhaps you could think of the increase in mass as you remove a nucleon from its nucleus as the manifestation for the potential energy associated with the strong interaction? but not sure if that is correct at all.