After a beta+ decay, where does the positron and neutrino go? Do they stay in the nucleus or?
Depending on the surroundings, the positron will likely end up annihilating with an electron somewhere nearby. The neutrino most likely (and I mean that it is orders and orders of magnitude likelier than anything else) goes away never to be heard of by anyone or anything again. They have a tendency of interacting very very seldom.
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