Question

${}_{92}{U}^{235}$ nucleus absorbs a neutron and disintegrates into ${}_{54}X{e}^{139}$, ${}_{38}S{r}^{94}$ and x, What will be the product x?

• A. 3 neutrons
• B. 2 neutrons
• C. $2\alpha -particles$
• D. $2\beta -particles$

Answer 1

The correct option is A 3 neutrons

${}_{92}{U}^{235}+{}_0{n}^1\to {}_{54}X{e}^{139}+{}_{38}S{r}^{94}+{}_Z{X}^A$
Equating mass number on both sides,
235 + 1 = 139 + 94 + A

or, A = 3
Equating atomic number on both sides,
92 + 0 = 54 + 38 + Z

or, Z = 0
Hence, x = 3 neutrons