What Do We Understand by Atomic Model?
J.J. Thomson detected the electron in the year 1897. It was observed that as atoms had no charge and the electron and proton had opposite charges, the next step was to determine how these particles were arranged in the atom. As the size of the atom was extremely small, this was going to be a difficult task. The Scientists, therefore, set out to devise a model of what they thought the atom might look like. The final goal of each atomic model was to present all the experimental evidence of atoms in the simplest way possible
Plum Pudding Model
J. J. Thomson, who invented the electron in the year 1897, suggested the atom's plum pudding model in 1904 which was for including the electron in the atomic model. The electrons were assumed to be positioned in revolving circles around the atom in this model to be having a "cloud" of positive charge.
JJ Thomson Proposed that an atom consists of a positively charged sphere, and the electron was embedded into it.
II. In magnitude, the negative and the positive charges were equal. The whole atom was electrically neutral. But Thomson's model explained that atoms are electrically neutral, this model was not able to explain the experiments which were conducted by other scientists.
Limitations of JJ Thomson Model of Atom (Plum Pudding Model)
In magnitude the whole atom was electrically neutral. But Thomson's atom model failed to explain Rutherford's α-particle scattering experiment in which most of the fast-moving α - particles went through the gold foil straight away. Only some of the s clearly defined atoms had much empty space and the positive charge within the atom is concentrated in a very small volume. These were some of the drawbacks of the Thomson model of the atom which failed to explain the atom's stability and scattering experiment of Rutherford.
Conclusion
Atomic structures are intriguing and can be fun to learn. This article specifically deals with Thomson’s Atomic Model - Plum Pudding Model and the limitations it deals with. To have a thorough understanding, Please read it carefully and don’t just peruse.
FAQs on Thomson's Atomic Model
1. What was JJ Thomson's Atomic Model?
J J.J. Experiments with cathode ray tubes by Thomson showed that all the atoms contain tiny subatomic particles or electrons that are negatively charged. Thomson suggested the atom's plum pudding model, which had negatively charged electrons trapped in a "soup" filled with positive effect.
2. Why was JJ Thomson's Model Wrong?
At the time, Thomson's model was correct, because it explained everything scientists already understood about the atom. Thomson 's model was dismissed by the Japanese physicist Hantaro Nagaoka. He said a massive nucleus was in the atom. The electrons, like the rings revolving around Saturn, revolved around the nucleus.
3. Explain JJ Thomson's Contribution to the Atomic Theory?
In the year 1897 J.J. Thomson discovered the electron by playing with a tube that was Crookes, or cathode ray. He had shown that the cathode rays were charged negatively. Additionally, he also examined positively charged neon gas particles.
4. Why is the Plum Pudding Model Wrong?
In 1911, Rutherford proved that the Thomson hypothesis was "wrong": there was no uniform distribution of both positive and negative particles. Rutherford has shown the atom has a small, massive, positively charged nucleus in it. He has also confirmed with Nagaoka that the electrons move outside the nucleus in circular orbits.
5. What is the Importance of JJ Thomson’s Atomic Model?
JJ Thomson’s discovery in 1897 was a revolution for its time and a landmark occasion in the history of particle physics. In this model, for the first time the election was mentioned in the theory and the neutrality of the atom was established. This model was also known as the Watermelon model. Although this model was not perfect and it turned out that there were some flaws.
6. Why is Thomson’s Atomic model also known as the Watermelon Model?
The JJ Thomson model is also called the atomic watermelon model because it resembles both spherical plum pudding and watermelon. It is also compared to watermelon because the red edible part of the watermelon is compared to a positively charged sphere and the black seeds that fill the watermelon resemble the electrons of the sphere.
7. What was the Rutherford Experiment?
In 1909, the physicist Rutherford along with Ernest Marsden performed an experiment which is known as the Rutherford alpha scattering experiment was fired at a foil of gold leaf and it was observed that there were diversions in the track of alpha particles but the diversion was not equal for all particles, some alpha rays faced no diversion while some rays were reflected at 180 degrees. This experiment proved the existence of empty space in an atom.
8. What is an Alpha Particle?
An Alpha particle, also known as alpha rays or alpha radiation, consists of protons and neutrons bound together into a particle which is identical to a helium 4 nucleus. They are generally produced by the process of alpha decay. Once the ion receives two elections, it turns into the Helium Atom.
9. What do the Latest study on Electrons and the Model of the Atom tell us?
According to the latest research, The orbital theory of elections has been the most exciting field where electrons are considered as clouds of negative charge which is present in orbital lobes around the nuclei. These clouds are not static and are part of a wave function. It is also important to note that the orbitals are of different shapes depending on the electron being present in the s,p,d, or f electron orbital level. The orbital model has been very successful in explaining the presence of resonance in benzene and other organic compounds.
