Question

Neutron was discovered by:
(A) J.J. Thomson
(B) Chadwick
(C) Rutherford
(D) Priestley

Answer 1

Hint: Neutron is a very tiny particle that is too small to even see. They are like protons and electrons except they don't possess any charge. A British physicist discovered neutrons in 1932.

Complete answer:
* In 1920, Rutherford, who discovered the atomic nucleus in 1911 and observed proton in 1919, proposed that electron and proton combined to form a new, neutral particle, but he failed to provide any evidence for this and told that this neutral particle would be difficult to detect.
* Neutron was discovered by James Chadwick in May 1932. After experimenting for only about two weeks in February 1932, he was able to publish a paper titled, "The Possible Existence of a Neutron", which included his proposition about the evidence favoured the possibility of a neutron rather than the gamma ray photons as the correct interpretation of the mysterious radiation.
* Then a few months later in May 1932, he announced that the core of an atom contained a particle that was neutral in charge, which he called neutron.
* The discovery of Neutron changed the view of an atom and Chadwick was awarded with the Nobel Prize in 1935 for his amazing discovery of a Neutron.

Note: Neutron is a neutral particle which is a constituent of every atomic nucleus except the one of ordinary hydrogen. It has no electric charge and has a mass of $1.67493 X {10}^{-27} kg$ which is greater than proton and nearly 1839 times greater than that of an electron.