Edit: I believe this might be in the wrong forum, if it is I am sorry I don't know how to delete or move :( Hey guys quick question! I am studying basic radioactivity just for fun and ran into something that my text doesn't elaborate on. Could someone please clarify? The mass of Helium-4's nucleus is 4.0026 amu, but the mass of a proton is 1.00783 and a neutron is 1.00866. Do the math and we are missing 0.03038 amu from the theoretical and the actual mass. The text atributes this missing mass to the 'Binding Energy' of the nucleus. Converting that mass into energy 28 MeV.... 7MeV per Nucleon. Okay so basicly what I am asking is how is this mass that is lost taken from the nucleon, or the neutron to be more exact? The text states that their is a relationship between the neutron and the binding energy. Is just a little bit of mass 'chipped' off each neutron and used as the binding energy? I just keep thinking of how this mass could be lost, but I can always shoot down any possible solution I am able to come up with. I am sure tho it has to do with the residual strong force and the gluons being exchanged. Maybe there is a special property of the up,down,down configuration of a neutron? I have also read about something called 'rest mass' but am not to familar with it. Could it be that gluons have no mass while in transit, but mass while 'resting'? My text says gluons have mass .... but if they don't have mass while being exchanged one can assume that there will always be exchanging done and there will always be some missing mass, aka the binding energy. And well if my hypothesis is correct then I guess you could assume the replusion of the protons override the attraction of the gluons and therefore neutral agents, neutrons are needed to supply the extra gluons/residual force to bind the nucleus together. And a little off topic: A quark loses some mass when releasing a gluon, while the accepting quark gains? Wew okay I have rambled on enough, I must say I have deepened my understanding of it just by the introspection I had to do by just asking this question. I started writing this without any idea, and then came out with a hypothesis while writing and even if it is completely wrong I still have learned so much and have developed a better picture of physics. Who would have thought asking a question would facultate learning :rofl: Well thank you for any input given!