Thomson Atomic Model

Time has passed since Dalton’s theory have been able to explain some complexion of the atom until 1897 when Joseph John Thomson discovered the electrons which has a huge impact of the existing atomic model of Dalton. From his cathode ray experiment, he learned and discussed about the existence of electrons. Cathode ray experiment explored on cathode ray tubes which are vacuum tubes that consist of one electrode one each side of the tube, altogether consisting of two electrodes, when one of the electrodes or the “cathode” launches electron at the other electrode or “anode”, the voltage is added to the system. While Thomson was performing this experiment, he unexpectedly saw a ray of “light” between the electrodes. At that time, he did not know

To clarify, he stated that the cathode rays had negative charge which is what is now called electrons. After wards, Thomson discovered the electrons, he created the “plum pudding model”, before the discovery of nucleus in 1904, which explained that the atom is composed of negatively charged “corpuscle” or electrons surrounded by the positively charge “soup” to balance out the negativity of the electrons. Or as referred to the name of the model, like negatively charged “plums” surrounded by a “pudding” which is positively charged, sometimes the atom can be called “cloud” of positive charge. In completion, Thomson’s final atomic model suggested that atom is a sphere with positive charge consisted of electrons inside, which means that the overall charge of the atom is neutral.

Unfortunately, it was suspected that Thomson’s theory did not support some aspect of the atomic structure. Ernest Rutherford, a New Zealand physicist, tries to prove the errors of

Niels Bohr, a Danish physicist, was asked to help solve the error in the Ernest Rutherford’s planetary model of atom from Rutherford himself. The problem of the planetary model was that Rutherford could not figure out why the electrons that has negative charge remain in the orbit but not attracted by the nucleus that has positive charge. As according to Maxwell's theory of electromagnetism which stated that the orbiting electron has acceleration which will release electromagnetic radiation. And while the electron releases radiation continuously, the energy would decrease and the electron will get pulled into nucleus, meaning that all atoms were unstable. An addition problem of the planetary model was that the model shows that while the electrons spiraled inward, the emission would increase in frequency making the orbit decrease in size and increase its speed. Yet most experiments during that period showed that atoms only release electromagnetic energy at a specific frequencies. Therefore, to overthrown those conflicts, Niels Bohr created the Bohr Model of Atom in 1913 which consisted of 4 main ideas. Altogether, the Bohr model proposed that electrons are only present in stable orbits, around the nucleus, called “stationary” orbits. Each of the orbits has a specific corresponding energy and the electron can gain energy when it jumps to a higher orbit but it will lose energy