[Chemistry Class Notes] on Thomson's Atomic Model Pdf for Exam

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.