Question

Neutrons were discovered by:

• A. Bombarding thin sheets of beryllium with alpha particles
• B. Bombarding thin sheets of calcium with beta particles
• C. By radiating X-rays on an alpha particle
• D. Bombarding thin sheets of calcium with alpha particles

Answer 1

The correct option is A Bombarding thin sheets of beryllium with alpha particles

${}_2^{4}H{e}^{2+}+{}_4^{9}Be\to {}_6^{12}C+{}_0^{1}n$
Neutrons were discovered by the bombardment of alpha particles $\left({}_2^{4}H{e}^{2+}\right)$ on a thin sheet of beryllium $\left({}_4^{9}Be\right).$