Question

Write a brief description about the discovery of electrons.

Answer 1

Atoms and nuclei:

1. The atom is the smallest component of an element, which is having electrons, protons, and neutrons in it, with protons and neutrons in its nucleus and electrons revolving around the nucleus.
2. Electrons were discovered through various experiments with a cathode ray discharge tube as the main experiment.

Cathode ray experiment by J.J. Thomson:

1. He built a glass tube in such a way that most of the air was pumped out. Then he used two electrodes at either end of the tube to apply a large electrical voltage. He noticed a stream of particles traveling from the negatively charged electrode to the positively charged electrode. The ray is known as a cathode ray, and the entire structure is known as a cathode ray tube.
2. The ray followed a set of rules.
3. They were unaffected by the cathode's material composition.
4. When an electric field is applied to the cathode ray path, the ray is deflected towards the positively charged plate. As a result, negatively charged particles make up the cathode ray.

Oil Drop Experiment by Millikan:

1. Millikan determined the charge of electrons through his Oil Drop Experiment.
2. An electron's measured charge (e) is $1.601019\mathrm{C}$. The mass of the electron can be calculated using the measured charge of the electron and the e/m ratio provided by J. J. Thomson's cathode ray experiment.