The scientific magazine Nature published on February 7, 1932 an article by James Chadwick that would change our conception of matter, entitled Possible Existence of a Neutron. A few months later, on June 1, the article in which the physicist and Nobel laureate finally proved the existence of the neutron was published in the Royal Society.
Chadwick bombarded a thin sheet of beryllium with alpha particles, and the metal emitted very high-energy radiation, similar to gamma rays. Later experiments showed that these rays actually consist of a third type of subatomic particle, which Chadwick called neutrons because they were electrically neutral. With this discovery, for the first time, a complete picture of the atom was offered, something of capital importance for physics and chemistry.