Ernest Rutherford was a New Zealand-born British physicist, known 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 that we use today. Without his contributions, we would still be using the outdated and incorrect Plum Pudding model, and we would have less understanding of how atoms form the world around us.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 discoverer of the electron in 1897, JJ Thompson. This was the most common model of the atom and indicated that electrons (plum) floated freely in a positively charged mass (pudding), hence the name "plum pudding". There were no other subatomic particles in the diagram, because they had not been discovered at the time of JJ Thompson's model of the atom, but the atom was known to have neutral, so the Thompson's theory of the positive cloud replaced protons. Thompson's model had several problems, including the lack of a nucleus containing protons, which led Thompson and other scientists to believe that the atom possessed electrons to balance its positively charged nature and give it a neutral charge. Although this theory was widely accepted, some scientists speculated that Thompson's model was incorrect, one of them being Hantaro Nagaoka who countered Thompson's model with the argument that opposite charges do not cannot leak into each other, so the positive charge held by the atom must be concentrated in the nucleus and the electrons would circle around the outside. Rutherford's experiment will prove Nagaoka right, ...... middle of article ...... 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 exterior of the nucleus a large distance, hence the low area density and large mass. Together, all of 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 is not the model we use now, because neutrons are still missing, but the discovery of the nucleus helped other scientists find the neutron. Under Rutherford's leadership, 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.