Answer:
one that has an unstable nucleus
Explanation:
An isotope is defined as a chemical variant present in an atom with different number of neutron but same number of protons.
Radioactive decay is the sudden breakdown of an atomic nucleus allowing matter and radiation to be emitted from the nucleus. A radioisotope with unstable nuclei undergoes radioactive decay because they do not have adequate binding energy to keep the nucleus together. there are four types of Alpha, Beta, Gamma Decay and Positron Emission.
Hence, the correct option is "one that has an unstable nucleus"
<span>swimming by large fish</span>
Answer: 70%, although that is an estimation because it is 71%
