Question

In an atom bomb, the energy is released because of the:
(a)- Chain reaction of neutrons and $_{92}{{U}^{238}}$
(b)- Chain reaction of neutrons and $_{92}{{U}^{235}}$
(c)- Chain reaction of neutrons and $_{92}{{U}^{236}}$
(d)- Chain reaction of neutrons and $_{92}{{U}^{240}}$

Answer 1

Hint: An atom bomb is a substance that is used for explosions in a very large area because of the enormous amount of energy produced. This is due to the chain reaction occurring between neutrons and uranium. The difference in the mass number and an atomic number of the uranium in the atom bomb is 143.

Complete answer:
We know that there are two processes in which a very huge amount of energy is released, i.e., nuclear fission and nuclear fusion. In nuclear fission, the larger nuclei will split into smaller suitable nuclei which release energy while in nuclear fusion smaller nuclei will combine to form heavy nuclei.
In an atom bomb, nuclear fission takes place. An atom bomb is a substance that is used for explosions in a very large area because of the enormous amount of energy produced. This is due to the chain reaction occurring between neutrons and uranium. The reaction takes place between neutrons and $_{92}{{U}^{235}}$. In this reaction, the uranium will react with neutrons and will convert into barium, krypton, and three neutrons, and releases the energy of around 200 MeV. The reaction is given below:
$_{92}{{U}^{235}}{{+}_{0}}{{n}^{1}}{{\to }_{36}}B{{a}^{141}}{{+}_{56}}K{{r}^{92}}+{{3}_{0}}{{n}^{1}}+200MeV$
The three neutrons produced in this reaction will further react with other uranium molecules until all the uranium molecules are consumed.

Therefore, the correct answer is option (b)- Chain reaction of neutrons and $_{92}{{U}^{235}}$ .

Note:
In nuclear fission, there is a requirement of a specific temperature, so when the temperature is attained then only the reaction will occur. An example of nuclear fusion is the reactions taking place in the sun.