Which equation represents a fission reaction?
A.
\ce
0
1n+
92
235
U−>
55
140
Cs+
37
94
Rb+2
0
1
n
B.
\ce
2
4
Be+
2
4
He−>
6
12
C+
0
1
n
C.
\ce
93
233
Np−>
94
239
Pu+e
−
The Correct Answer and Explanation is :
The correct answer is A:
[
\ce{^{235}{92}U + ^{1}{0}n -> ^{140}{55}Cs + ^{94}{37}Rb + 2^{1}_{0}n}
]
Explanation of Fission Reactions
Nuclear fission is the process where a heavy atomic nucleus splits into smaller nuclei along with the release of energy. This reaction typically occurs when a neutron collides with a heavy nucleus, such as uranium-235 ((^{235}{92}U)). In the equation given in option A, a neutron ((^{1}{0}n)) interacts with uranium-235, leading to its fission.
Upon absorption of the neutron, the uranium nucleus becomes unstable and splits into two smaller nuclei, cesium-140 ((^{140}{55}Cs)) and rubidium-94 ((^{94}{37}Rb)). Importantly, this fission reaction also releases two additional neutrons ((2^{1}_{0}n)) and a significant amount of energy, which is a hallmark of fission processes. This energy release is what makes fission a powerful source of energy for nuclear reactors and atomic bombs.
Analyzing the Other Options
- Option B:
[
\ce{^{4}{2}Be + ^{4}{2}He -> ^{12}{6}C + ^{1}{0}n}
]
This reaction is an example of nuclear fusion, where two light nuclei combine to form a heavier nucleus (carbon-12, (^{12}_{6}C)) and a neutron. Fusion typically occurs in stars and involves the combination of light elements, contrasting sharply with fission, which deals with heavy elements.
- Option C:
[
\ce{^{233}{93}Np -> ^{239}{94}Pu + e^{-}}
]
This reaction represents beta decay, not fission. In beta decay, a neutron in the nucleus is converted into a proton while emitting a beta particle (electron, (e^{-})). Although related to nuclear processes, it does not involve the splitting of a nucleus into smaller fragments.
In summary, option A is the correct representation of a fission reaction, highlighting the critical nature of neutron interactions with heavy nuclei that lead to energy release.