Q 12-13-008NEETNEET 2020Top questionEasy
When a uranium isotope $^{235}_{92}\text{U}$ is bombarded with a neutron, it generates $^{89}_{36}\text{Kr}$, three neutrons and :
Answer: (A) $^{144}_{56}\text{Ba}$
Concept. In a nuclear reaction both the mass number and the charge number are conserved.
Step 1. Reaction.
$$^{235}_{92}\text{U} + {}^1_0n \rightarrow {}^{89}_{36}\text{Kr} + 3\,{}^1_0n + {}^A_ZX$$
Step 2. Mass number. $236 = 89 + 3 + A \Rightarrow A = 144$.
Step 3. Charge. $92 = 36 + Z \Rightarrow Z = 56$ (barium).
Answer. $^{144}_{56}\text{Ba}$ (Option A).
Solution by Sreeraj P, M.Sc Physics