Question

${}_{{\text{92}}}{{\text{U}}^{{\text{235}}}} + {}_{\text{0}}{{\text{n}}^{\text{1}}} \to {}_{{\text{38}}}{\text{S}}{{\text{r}}^{{\text{92}}}} + {}_{{\text{54}}}{\text{X}}{{\text{e}}^{{\text{141}}}} + 2{}_{\text{0}}{{\text{n}}^{\text{1}}}$.
The above reaction is an example of:
A. Uranium fusion
B. Uranium fission
C. Artificial transmutation
D. None of the above

Answer 1

We are given a reaction in which the uranium nucleus ${}_{{\text{92}}}{{\text{U}}^{{\text{235}}}}$ reacts with a neutron and undergoes and produces two lighter nuclei ${}_{{\text{38}}}{\text{S}}{{\text{r}}^{{\text{92}}}}$ and ${}_{{\text{54}}}{\text{X}}{{\text{e}}^{{\text{141}}}}$ along with two neutrons. Thus, we can say that a heavy unstable nucleus absorbs a neutron and energy and disintegrates into lighter nuclei and some neutrons.

Complete step by step solution:
The given reaction is,
${}_{{\text{92}}}{{\text{U}}^{{\text{235}}}} + {}_{\text{0}}{{\text{n}}^{\text{1}}} \to {}_{{\text{38}}}{\text{S}}{{\text{r}}^{{\text{92}}}} + {}_{{\text{54}}}{\text{X}}{{\text{e}}^{{\text{141}}}} + 2{}_{\text{0}}{{\text{n}}^{\text{1}}}$.
We are given a reaction in which ${}_{{\text{92}}}{{\text{U}}^{{\text{235}}}}$ absorbs a neutron and disintegrates into two lighter nuclei ${}_{{\text{38}}}{\text{S}}{{\text{r}}^{{\text{92}}}}$ and ${}_{{\text{54}}}{\text{X}}{{\text{e}}^{{\text{141}}}}$ along with two neutrons. Thus, we can say that a heavy unstable nucleus absorbs a neutron and energy and disintegrates into lighter nuclei.
The given reaction involves splitting of heavy radioactive nuclei into smaller nuclei by releasing large amounts of energy. This is known as nuclear fission
In nuclear fission, an unstable nucleus disintegrates and undergoes fission and splits into a lighter nuclei.
The unstable nucleus undergoes fission when it is bombarded by neutrons. In a controlled nuclear fission, the number of neutrons can be restricted by slowing down the neutrons.
Thus, when ${}_{{\text{92}}}{{\text{U}}^{{\text{235}}}}$ nucleus absorbs a neutron i.e. when ${}_{{\text{92}}}{{\text{U}}^{{\text{235}}}}$ nucleus undergoes a controlled nuclear fission it disintegrates into two lighter nuclei ${}_{{\text{38}}}{\text{S}}{{\text{r}}^{{\text{92}}}}$ and ${}_{{\text{54}}}{\text{X}}{{\text{e}}^{{\text{141}}}}$ along with two neutrons.
Thus, it is a uranium fission reaction.

**Thus, the correct option is (B) uranium fission.

Note: **
In a nuclear fission, a heavy nucleus disintegrates into lighter nuclei. Large amount of energy is released during nuclear fission. The energy produced in a nuclear reactor can be used to fulfil electrical energy requirements. Nuclear fission occurs by itself and no additional energy is required for a nuclear fission to occur.