Question

when is it said to be that nucleas is unstable????

Answer 1

Unstable Nuclei. In unstable nuclei the strong nuclear forces do not generate enough binding energy to hold the nucleus together permanently. It is unstable nuclei that are radioactive and are referred to as radioactive nuclei and in the case of their isotopes called radioisotopes.An atom is unstable (radioactive) if these forces are unbalanced; if the nucleus has an excess of internal energy. Instability of an atom's nucleus may result from an excess of either neutrons or protons.

Answer 2

When the nucleus atom in the chain is not finishing and continue the chain is working than we can say that the nucleus is not stable now

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