Question

The discovery of neutron was made by

• A. Chadwick
• B. Rutherford
• C. Becquerel
• D. Curie

Answer 1

The correct option is A

Chadwick

The explanation for the correct option

Option A

1. In the year $1932$, British physicist Sir James Chadwick discovered neutrons. For this discovery, he received the Nobel Prize in Physics in $1935$.
2. It’s worth noting that Ernest Rutherford proposed the neutron theory in $1920$.

The explanation for the incorrect options

Option B.

1. Ernest Rutherford is well recognized for his groundbreaking research into radioactivity and atom. He discovered that uranium produces two forms of radiation: beta and alpha particles.
2. He found that an atom is mainly empty space, with its mass centered in a positively charged nucleus at the center.

Option C.

1. In 1896, Henri Becquerel researched the newly discovered $X-$rays, which led to research into how light affects uranium salts.
2. He discovered that uranium salts emit penetrating radiation that can be recorded on a photographic plate by accident. Further research revealed that this radiation was not $X-$ray radiation, but rather a new phenomenon known as radioactivity.

Option D

1. Madame Marie Curie is most known for discovering radium and polonium, as well as her significant contribution to cancer research.

Therefore, Neutron is discovered by Chadwick. Hence, Option A is correct.