Hi I don't understand my textbook 100% when it comes to this: Weak nuclear force: The force that affects leptons and quarks. Uhm, how? They tried to illustrate this with an example of a beta-decay, but I didn't get it. Some W- particle was created when an d quark went over to an u quark, and the W particle again turned into an electron and an anti neutrino. Question: Does an u quark have less, uhm, potential energy than a d quark? I think I remember that if protons receive enough energy they'll turn into a positron + a neutron. Strong nuclear force: Apparently the force particle, gluon, can "glue" quarks, and thus protons&neutrons, closer together the further away they are, until a certain limit where the gluon has no influence any-more, correct? If the strong nuclear force gets stronger over distance until a certain point, why are the heavy radioactive atoms so unstable? I mean there are neutrons&protons all over the place to counteract the EM force, kind of weird that they would lose the battle of keeping the atom against the EM force. Also some more questions: In the model for alpha decay they say that alpha particles are down in an "energy well" waiting to get out and they start talking about stuff like borrowing energy from nowhere and then paying it back later (good thing nature doesn't take rents- haha). Two questions: 1) wouldn't it be more correct to say that the alpha particle has a certain probability of "breaking out", with that probability rising with the particle's kinetic & potential energy? 2) What if the alpha particle has absolutely zero kinetic or potential energy, and it needs 1 Joule to break out? It borrows 1 joule to break out, and it is out of the alpha particle. But then it has zero kinetic or potential energy, because it has broken out.. What will it pay back the bill with (maybe it has its mass as a security :) )?