Ernest Rutherford was born August 30, 1871 in New Zeland. Rutherford earned his bachelors and his masters of Arts and was in first-class honors in math and science at Canterbury College. In 1900 after doing research at Canterbury College, Ernest got married to the love of his life Mary Newton and they had a daughter. After settling down Ernest continued his research and one day came up with an experiment to test the plum pudding model of the atom. This is where the beginning of the new atomic model began.
Rutherford's Atomic Model
After finding the results to his Gold Foil Experiment which was conducted by his two associates in 1908, Hans Geiger and Ernest Marsden, Rutherford concluded a new atomic model must be created because the plum pudding model was incorrect. So in 1909, Rutherford began working on a new model and found the Nucleus by proposing the idea that perhaps the positively charged subatomic particles were not scattered within the atom but all condensed into one place in the atom. After many experiments, Rutherford turned this hypothesis into a theory! In finding the nucleus Rutherford used his theory, the Nuclear Theory, that states the nucleus takes up over 99% of an atom, all of the subatomic particles that create the nucleus are positively charged and those subatomic particles are called protons. Then Rutherford went even deeper into this by explaining the electrons and their purpose in another thing he named the "electron cloud". The electron cloud takes up the majority of the volume of an atom, with a ration of 10^14 :1 which means the electron cloud's volume is one hundred trillion times larger in terms of volume than the nuclei. He also stated the electron cloud contains all of an atoms negative charge. Through all of these studies and the results to various experiments and most importantly the Gold Foil experiment, Rutherford was able to create the new and improved atomic model, . This model was discovered and created mainly because the predicted existence and discovered existence of the nucleus that Rutherford took part in. Rutherford's atomic model is known as The Rutherford Model of the Nuclear Atom due to the discovery of the nucleus! This model was officially developed around the year 1911!
Gold Foil Experiment
In 1911 Rutherford was aware of the only known subatomic particle, the electron. Earlier in science, J.J. Thomson had suggested a model called the "plum pudding model." In this model the subatomic particles are scattered through the atom and have electrons dispersed through this positively charged "jelly". Rutherford planned to test Thomson's hypothesis and model by doing and experiment called the Gold Foil Experiment. So the experiment was conducted with a source that gave off positively charged alpha particles towards a gold piece of foil. There was a ring around the foil that acted as a detector to see where the alpha particles ended up. Testing J.J. Thomson's atomic model the alpha particles should go through the foil and end up on the other side for the most part. They then carried through with the experiment and found that the alpha particles did indeed go through the foil but then bounced back and around the detector. The particles would often scatter and their scattering rate directly corresponded with the atomic weight of the target. Also the two conductors of the experiment, Geiger and Marsden, noticed certain scattering patterns on the degrees of the angles they bounced of the detector at. It was hard to understand and didn't make sense. So they concluded the plum pudding model wasn't quite correct so they began to create a new model. While creating a new model, the Nuclear Theory was developed.