what type of isotope undergoes radioactive decay?\no one that has a nucleus with the same number of protons…

what type of isotope undergoes radioactive decay?\no one that has a nucleus with the same number of protons and neutrons\no one that has an unstable nucleus\no one that has the same number of protons and electrons\no one that has a stable nucleus
Answer
Brief Explanations:
Radioactive decay occurs in isotopes with unstable nuclei. Unstable nuclei try to gain stability by emitting radiation. Isotopes with stable nuclei do not undergo radioactive decay. Having equal numbers of protons and neutrons or protons and electrons does not determine if an isotope will decay.
Answer:
one that has an unstable nucleus