Question

mass of electron..and how rutherford derived it??

Answer 1

Electron was discovered by J. J. Thomson in 1897 when he was studying the properties of cathode ray.. 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.