Lorien Stanford and Muqadas Swati Sir James Chadwick Lorien Stanford and Muqadas Swati

The atom before Until 1932, scientists believed that the atom had a positively charged nucleus that are surrounded by negatively charged electrons.

The discovery of the Neutron When James Chadwick attacked alpha particles with beryllium atoms, an unknown radiation was produced. He thought this radiation was made of particles with a neutral electrical charge and had the about the same mass of a proton. This particle is now known as a neutron.

How he discovered the neutron Most researchers believed there were electrons within the nucleus as well as outside it. Rutherford, Chadwick, and some other scientist believed in the possibility that particles with no charge could be in the nucleus. During the 1920s, Chadwick conducted different experiments in the lab, trying to find the neutral particles, he was looking for. Even though all his test failed he was still convinced that this particle existed. In 1932, After years of failed test Chadwick heard about the work that Frederic and Irene Joliot-Curie had just done in Paris. They believed they had managed to eject protons from a sample of wax using gamma rays. Chadwick, was confused by these results because he thought gamma rays were not powerful enough to do this. So he came to the conclusion that the protons had been hit by the particle he was looking for “the neutron”. He started to perform the same test the Joliot-Curies performed and measured the protons behavior, he came to the conclusion that the protons behaved in the exact way the should if they had been hit by a neutral particle that was about the same size as the proton, therefore proving that neutron existed.

citations "James Chadwick." Famous Scientists. famousscientists.org. 8 Sep. 2014. Web. 3/25/2018 <www.famousscientists.org/james-chadwick/>.