Hi, Explain in terms of the number of nucleons and the forces between them, why argon-36 is stable and argon-39 is radioactive. My first doubt regards the number of nucleons. If a nucleon is the collective number of neutrons and protons, if we take carbon 12 for example, does it have 6 or 12 nucleons? So, from what I understand, the greater the binding energy, the greater the stability. Unstable nuclei will decay, that is, give out energy (radioactively for example) in order to approach a more stable arrangement. Argon 39 would therefore be less stable than Argon 36 due to the fact it has three more neutrons and, hence, since neutrons weigh more than protons, have more mass, which translates into less binding energy? Does that explain why each is stable or radioactive? Can someone please guide me with this? Thanks!