Question

Describe the discovery of electrons and protons

Answer 1

The discovery of electrons took place when J.J Thompson took the air out of a tube with a fluorescent material in one end. When he gave 10000 V of power to it, he could see some spots in the screen. He called this as cathode rays. Later he named them as electrons. Goldstein discovered the protons. When he made the pressure inside the container lesser and did the same as Thompson did, he found that a red glow appeared on the end of the tube. He then found that they were because of protons.

Answer 2

Electron was discovered by J. J. Thomson in 1897 when he was studying the properties of cathode ray.
n 1909, Rutherford discovered proton in his famous gold foil experiment.
J. J. Thomson constructed a glass tube which was partially evacuated i.e. much of the air was pumped out of the tube. Then he applied a high electrical voltage between two electrodes at either end of the tube. He detected that a stream of particle (ray) was coming out from the negatively charged electrode (cathode) to positively charged electrode (anode). This ray is called cathode ray and the whole construction is called cathode ray tube. 
In his gold foil experiment, Rutherford bombarded a beam of alpha particles on an ultrathin gold foil and then detected the scattered alpha particles in zinc sulfide (ZnS) screen.