The neutron the curie family's legacy

This article is concerned with the scientific developments that led to the discovery of the neutron by Sir James Chadwick at the Cavendish Laboratory Cambridge in 1932. The Rutherford atom with a heavy nucleus and the problem of the 'intra-nuclear' electrons (needed to reconcile nuclear mass and charge) coupled with Marie Curie's discovery of radium as a prime example of natural radioactivity coming from the nucleus were key milestones. Fŕd́ric Joliot and Ir̀ne CurieJoliot almost discovered the neutron in 1931. But the predisposition of the thinking in Chadwick's laboratory allowed conclusive identification of the emission of a heavy neutral particle to be published about a month after the CurieJoliot experiment. Their Nobel Prize came a few years later with the discovery of artificial radioactivity.