The correct reaction taking place in a nuclear fission reactor is:
[tex]\[ { }_{02}^{205} U +{ }_0^1 n \rightarrow{ }_{30}^{04} Kr +{ }_{60}^{130} Ba +3{ }_0^1 n \][/tex]
Here's a detailed explanation of why this is the correct reaction:
1. Understanding Nuclear Fission:
- Nuclear fission is a process in which the nucleus of a heavy atom (typically uranium or plutonium) splits into two or more smaller nuclei, along with a few neutrons and a large amount of energy. This process is utilized in nuclear reactors to generate energy.
2. Identifying the Heavy Nucleus:
- In nuclear fission, a heavy nucleus such as uranium-235 or plutonium-239 is commonly used. Among the given reactions, the fourth reaction involves uranium ([tex]\( U \)[/tex]), which is a heavy element and known to be used in nuclear fission.
3. Interaction with a Neutron:
- The process starts when a nucleus like uranium captures a neutron ([tex]\( { }_0^1 n \)[/tex]).
- The fourth reaction shows uranium-205 capturing a neutron.
4. Splitting into Smaller Nuclei:
- The uranium nucleus then splits into smaller elements which are closer to the mid-range of the periodic table (like krypton ([tex]\( Kr \)[/tex]) and barium ([tex]\( Ba \)[/tex]) in the given reaction).
- The products of the reaction include krypton-104 and barium-130, which fit this description.
5. Release of Neutrons:
- In addition to the smaller nuclei, nuclear fission reactions typically release additional neutrons. In the given reaction, 3 neutrons ([tex]\( { }_0^1 n \)[/tex]) are released, which is characteristic of such a process.
To sum up, the fourth reaction:
[tex]\[ { }_{02}^{205} U +{ }_0^1 n \rightarrow{ }_{30}^{04} Kr +{ }_{60}^{130} Ba +3{ }_0^1 n \][/tex]
fulfills all the conditions of a nuclear fission reaction in a reactor: involving a heavy nucleus (uranium), capturing a neutron, splitting into smaller nuclei, and releasing additional neutrons. Therefore, it is the correct reaction taking place in a nuclear fission reactor.
