Question

Assertion :$U^{235}$ nucleus, by absorbing a slow neutron undergoes nuclear fission with the evolution of a significant quantity of heat Reason: During nuclear fission a part of the original mass of $U^{235}$ is lost and gets converted into heat.

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is correct but Reason is incorrect
• D. Both Assertion and Reason are incorrect

Answer 1

The correct option is A Both Assertion and Reason are correct and Reason is the correct explanation for Assertion

$\begin{array}{c}{}_{92}{U}^{235}+1_0{n}^1{\to }_{56}B{a}^{144}{+}_{36}K{r}^{89}+3_0{n}^1\end{array}$

$\begin{array}{c}\text{The above reaction is the fission}\\ {\text{reaction by which}}_{92}{U}^{235}\\ \text{undergoes nuclear fission.}\\ \text{\&, energy lost in the process}\\ =200\text{Mev}\end{array}$

$\begin{array}{c}\text{i.e.}△m{c}^2=200MeV\\ \Delta m=\text{mass lost}\approx 0.1\%\\ \text{we can see above, the}\\ \text{mass is lost and converted}\\ \text{into heat.}\\ \text{option}A\text{is correct.}\end{array}$