How Ernest Rutherford Contributed to the Atomic Theory
Ernest Rutherford contributed to the atomic theory greatly and in a number of ways. In 1901 Rutherford was assisted with his work on radioactivity by British chemist Frederick Soddy. Before a year had passed they attained that upon the discharge of radiation, causes a radioactive atom to change to another atom. A paper was issued by both scientists on the theory of “spontaneous transformation of radioactive materials and radioactivity, and the source and characteristics of radioactivity. Rutherford was also able to practise on alpha particles, and issued a paper on the alteration of radioactivity. With Frederick Soddy's assistance, Rutherford had answered numerous questions to do with radioactivity. He recognised that atoms that are radioactive alter instinctively to different atoms. This idea was classified as isotopes.
During 1911 an idea regarding the existence of the atomic nucleus was put forward by Rutherford. This was his most innovative idea, and was supported by his famous Gold Foil Experiment. Two of Rutherford's employees discovered that when alpha particles were shot at an emaciated foil of metal, numerous particles were rebounded. This was explained by Rutherford as the planetary model of an atom, where the whole positive charge of an atom is in the tiny nucleus, while the negative charged, electrons occupy the area around the nucleus, which showed that atoms are mostly empty space.
apparatus with which Rutherford first observed artificial transmutationDuring 1917, Rutherford was convinced that he had ascertained a study comprising of the simulated alteration of nitrogen (splitting of the atom). One year later the position of Cavendish professor at Cambridge befell him, and the simulated alteration of nitrogen was declared as definite. The experiment that Rutherford used to determine this was as follows:
1. Alpha particles from polonium pass through nitrogen gas
2. One alpha particle collides with a nitrogen nucleus
3. A hydrogen nucleus is expelled and an oxygen nucleus formed.
The above experiments made by Ernest Rutherford affected the development of the atomic theory greatly. The Plum Pudding model of an atom, where the negative charge is dispersed within the positive was proposed by Joseph John Thomson.
This was invalidated by Ernest Rutherford's planetary model of the atom, where the negative charges orbit the dense, nano-sized nucleus where the positive charge is located. This was important because Rutherford proved that the electrons were located on the outside of the nucleus, which meant that they were mobile. Because of this discovery we now know that the electrons orbiting the nucleus are responsible for the reactivity of the atom.
The Rutherford model of the atom was modified by Niels Bohr's model of the atom. This new model was similar to Rutherford's model but what Rutherford had failed to consider the energy levels of atoms. This Bohr did and adjusted the model of the atom so that the negative charge orbited the nucleus in shells (amounts of shells depend on the energy levels) and in a circular pattern.
The Plum Pudding model proposed by Joseph John Thomson.
The Planetary model of the atom proposed by Ernest Rutherford.
The Bohr model of the atom proposed by Neils Bohr.