Question

Which of the following reactions led to the discovery of neutrons?

• A. ${}_6{C}^{14}{+}_1{p}^1\to$ ${}_7{N}^{14}{+}_0{n}^1$
• B. ${}_{4}B{e}^9{+}_{2}H{e}^4\to$ ${}_6{C}^{12}{+}_0{n}^1$
• C. ${}_5{B}^{11}{+}_1{D}^2\to$ ${}_6{C}^{11}{+}_0{n}^1$
• D. ${}_{4}B{e}^8{+}_{2}H{e}^4\to$ ${}_6{C}^{11}{+}_0{n}^1$

Answer 1

Answer: (B)

${}_{4}B{e}^9{+}_{2}H{e}^4\to$ ${}_6{C}^{12}{+}_0{n}^1$

Rutherford suggested that in an atom, there must be present the third type of fundamental particle which is electrically neutral and he proposed the name, neutron.

Chadwick bombarded $Be$ with $\alpha$ - particles. The reaction which led to discovery of neutrons is as follows:

${}_{4}B{e}^9{+}_{2}H{e}^4\to$ ${}_6{C}^{12}{+}_0{n}^1$,

where ${}_{2}H{e}^4$ is $\alpha$ - particle and ${}_0{n}^1$ is neutron.