Answer:
the atom to become unstable and rip apart.
Explanation:
We define radioactivity as the spontaneous disintegration of atoms. It could occur naturally or artificially.
Artificial radioactivity occurs either by the process of nuclear fusion (combination of two light nuclei) or nuclear fission(bombarding of a heavy nucleus with a small particle such as a neutron).
When a heavy nucleus is bombarded with a neutron, the nucleus becomes unstable and rips apart producing a daughter nucleus/nuclei and more neutrons hence the process continues. This is otherwise called a chain reaction.
