Question

Give a reason for your answer.

Answer 1

Out of two isotopes of Uranium ${}_{92}{U}^{235}$ and ${}_{92}{U}^{238}$ given, ${}_{92}{U}^{235}$ is easily fissionable.
Since the nucleus having even atomic number-even mass number is the most stable isotope and rest are less stable isotopes. ${}_{92}{U}^{235}$ has even atomic number-odd mass number, so it is less stable and thus is easily fissionalbe.