Respuesta :
Those isotopes which are having unstable nucleus will undergo radioactive decay.
What are isotopes?
Isotopes are those species which are having same atomic number but different atomic masses.
Radioactive decay is a kind of nuclear reaction where an unstable nucleus losses energy in the form of radiation. Here the unstable nuclei are those in which very high or very few no. of neutrons are present as compared to the protons.
Hence, the unstable nucleus isotope undergoes radioactive decay.
Learn more about isotopes here:
brainly.com/question/160068
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