Discovery of Fission

• Rutherford described as the father of nuclear physics, bombarded alpha particles on Nitrogen to eject a proton and thus started the business of splitting atom in 1917.
• James Chadwick is credited with discovering neutron in 1932. Being neutral, it can easily penetrate the Columb barrier and interact directly with the nucleus.
• Enrico Fermi, considered to be one of the most brilliant physicist, postulated and succeeded in producing transuranic elements by bombarding neutrons on Uranium. However, he did not realise that he had fissioned Uranium in 1934.
• Otto Hahn, Fritz Strassman and Lise Meitner  in 1938 conducted experiments similar to Fermi.
• They noticed that instead of a heavy element formation they found lighter elements in the product.
• They were the first ones to postulate fission and pointed the large energy that will be released.
• We shall see later how this energy release is made possible.

Rutherford’s Model

• Rutherford, based on experimentation, had proposed a model for the atom.
• It has a central positively charged nucleus consisting of protons and neutrons.
• It has electrons revolving around to make the atom neutral.
• The charge and mass are summarised in the following table.