- Why is energy released when an atom decays into another atom, even though no energy is added?
- What does the mass defect mean?
Is it because a nucleus which decays is unstable (proton/neutron = 1)? For example, in large nucleons the electric force becomes dominant, therefore, it wants to get a better binding energy and decays, I think. Where does the required energy come from? It can go over the potential well, so it should tunnel, I suppose.
Is the energy release (mass defect) given by the relationship between the change in binding energy and mass via $E=mc^2$ where the daughter neuclus has a lower potential energy?
How is it even possible that an atom decays when no energy is added? Must it tunnel? How does it get over the barrier of the potential well?
I read this : How to explain $E=mc^2$ mass defect in fission/fusion
but i still don't understand it.