Hi all , I have a very simple doubt in the basics of radioactivity . Nuclear fission is the splitting of the nucleus of a heavy atom such as U23592 by bombarding with slow neutrons into two lighter nuclei with a simultaneous release of huge amount of energy . Now my doubt is that - Can a nucleus exist independently ? I mean in the nuclear fission process we talk about bombarding neutron on a heavy nucleus . But what about the electrons surrounding the nucleus ? And what about the electrons of the atoms of daughter nuclei? So is it basically bombardment of neutron on a heavy atom or a heavy nucleus ? I am asking this because in radioactivity we talk only about the nucleus not the atom . So what about the electrons orbiting the nucleus of atoms involved in the fission process ? I would appreciate if someone could help me understand this . Many Thanks .