Ernest Rutherford was a New Zealand-born British physicist, famous for "splitting the atom". His work on the gold foil experiment contributed greatly to the model of the atom and helped develop the standard model of the atom to the one we use today. Without his contributions we would still be using the Plum Pudding model, an outdated and flawed model, and would have less understanding of how atoms form the world around us. Before Rutherford's Geiger-Marsden experiment, the most popular model of the atom was the “plum pudding model” developed in 1904 by the person who also discovered the electron in 1897, JJ Thompson. It was the most common model of the atom and stated that electrons (plum) floated with free motion in a mass of positive charge (pudding), hence the name “plum pudding”. There were no other subatomic particles in the diagram, as they had not been discovered at the time of JJ Thompson's model of the atom, however the atom was known to be neutral, so Thompson's positive cloud theory replaced the protons. There were several problems with Thompson's model, including the lack of a nucleus with protons, which led Thompson and other scientists to believe that the atom had electrons to balance its positively charged nature and give the atom a neutral charge. Although this theory was widely accepted, some scientists theorized that Thompson's model was incorrect, one of these was Hantaro Nagaoka who countered Thompson's model with the argument that opposite charges cannot infiltrate each other, so the positive charge held by the atom must be focused in the atom. nucleus and the electrons would rotate around the outside. Rutherford's experiment would prove that Nagaoka was right, ... middle of paper ... this discovery of the “central charge” which was later renamed the nucleus, hence the current model of the atom. The current model of the atom shows a positively charged center, the nucleus with negatively charged electrons moving around the outside of the nucleus at a great distance, hence the low area density and large mass. Together, all this information proved that the plum pudding model was wrong, because the idea of ​​electrons floating in a positive gas could not produce these results. Rutherford's model of the atom Rutherford's model is not the model we use now, as neutrons are still missing, however the discovery of the nucleus helped other scientists find the neutron. Under Rutherford's guidance in 1932 James Chadwick discovered the neutron. This discovery led to the model we use today and would not have been possible without the discovery of the proton.