when did j. thompson discovered the charge-to-mass ratio for the electron using gas discharge tubes.
Electron Charge and Mass Quantity Symbol Value Units Mass me 9.109 x 10-31 kg Charge e 1.602 x 10-19 C I. The Charge to Mass Ratio (e/m) for the Electron Introduction In 1897 J. J. Thompson discovered the first elementary particle, the electron, by measuring the ratio of its charge to mass in a manner similar to the experiment that we will perform. Given the mass and