The Momentous Discovery of Neutron

The discovery of neutron ushered in a paradigm shift in our understanding of the subatomic world. The electrically neutral neutron does not experience Coulomb repulsion produced by the positively charged protons inside the nucleus. As a result, a neutron can penetrate deep into the nucleus and thus is a powerful probe to unravel the nuclear structure. In 1920, Rutherford prophetically predicted the existence of an electrically neutral particle inside the nucleus. It took more than a decade of painstaking experimentation to finally discover it in 1932. The historical aspects of a scientific discovery, for one reason or another, often, do not find their place in the normal discourse at both school and college levels. Studying the historical development of an idea can inspire, excite curiosity among, and familiarize students about how science works. In this article, we have tried to show how the relevant historical information can be integrated in traditional instructions while discussing the discovery of neutron which may enhance the curriculum outcomes and increase scientific literacy. We have discussed two important experiments that hinted at the existence of a new particle inside the nucleus. The arguments that led Chadwick to the ultimate discovery of neutron are also presented.