Question

How many neutrons result from the following fission reaction?
${}_{92}^{235}U{+}_0^{1}n{\to }_{40}^{94}Zr{+}_{52}^{139}Te+[?{]}_0^{1}n$.

• A. $1$
• B. $2$
• C. $3$
• D. $4$
• E. $5$

Answer 1

The correct option is C $3$

Let the number of neutrons emitted be $x$.

The given reaction : ${}_{92}^{235}U$ $+$ ${}_0^{1}n$ $\to$ ${}_{40}^{94}Zr$ $+$ ${}_{52}^{139}Te$ $+x_0^{1}n$

Conservation of mass number : $235+1=94+139+x$ $⟹x=3$