Question

On the basis of Thomson’s model of an atom, explain how an atom as whole is neutral.

Answer 1

Hint :The Thomson’s model was found when JJ Thompson performed his cathode ray tube experiment which gave some results, giving a plum pudding model of the atom in which electrons floated in a soup of diffused positive charges.

Complete Step By Step Answer:
In the above given question, we are being asked to explain the neutrality of the atom.
The Thompson’s model of an atom is called plum pudding model. Now before the plum pudding model few things were already stated regarding the atom, that all matter were composed of individual particles called atom, atoms of the same element have similar physical properties and that the atom was neutral. Now based on these Rutherford performed a cathode ray experiment in which two oppositely charged electric plates were placed around the cathode ray. The cathode ray was deflected towards the positively charged plate, away from nematically charged particles.
Now this gave the result that the cathode ray was a negatively charged particle, the particles must exist as part of the atom, since mass of each particle is very small even to the hydrogen atom.
Now based on these conclusions he gave the plum pudding model and also on the fact that the atom is neutral therefore there needs to be some positively subatomic particle. Now in the plum pudding he proposed that negatively charged particles were floating within a soup of diffuse positive charges.

Note :
After Thompson came Rutherford who denied this model as in Rutherford’s experiments it showed that there was something in the middle of the atom which deflected the rays completely one-eighty degree while Thompson said that all the rays went straight without getting deflected.