In Beta radioactive decay, how do quarks rearrange themselves in these situations? Do they do this? ß+ : 1p (2u, 1d) + energy ==> 1n (2d, 1u) + 1e- ß- : 1n (2d, 1u) ==> 1p (2u, 1d) + 1e- + energy I believe I have these right. Positive Beta decay is "endothermic" while negative Beta decay is "exothermic", because a neutron is bigger than a proton plus and electron, and so due to the conservation of matter, and E=mc^2, energy must make up the loss in mass. Please correct me if I'm wrong!