This question already has an answer here:

I know that when number of protons is high, the nucleus of atoms become unstable due to repulsive force and is radioactive. But why is that the nucleus also becomes unstable when there are too many neutrons?


marked as duplicate by John Rennie, Chris, Kyle Kanos, stafusa, Jon Custer Feb 8 '18 at 15:24

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

  • $\begingroup$ That question is not even close to my question $\endgroup$ – Hark Feb 8 '18 at 15:23
  • $\begingroup$ It happened that I read both. The moderators are right. The two Qs are basically the same. $\endgroup$ – Alchimista Feb 9 '18 at 9:59
  • $\begingroup$ What i mean is why does there have to be balance between no. of protons and neutrons. If there is high no. of neutrons then why would it be radioactive $\endgroup$ – Hark Feb 9 '18 at 13:43
  • $\begingroup$ Ok I see now what you mean. As for neutron being neutron and as such doing nothing .... Consider that neutron as free particle is unstable. Then is matter of nuclear physics . It makes sense to me that protons and neutron glue and stabilise themselves within a certain limit. Radioactivity presumes something stable enough (metastable) for the decay to occur. $\endgroup$ – Alchimista Feb 9 '18 at 14:00
  • $\begingroup$ Can you explain why a free neutron is unstable? $\endgroup$ – Hark Feb 9 '18 at 16:54