^Electrons

^Electrons

J. J. Thomson was the first to determine experimentally the speed and the specific charge (e/m) of the cathode ray particles.  He found

1. cathode rays travel with speeds ranging from about 0.1 to 0.2 times the speed of light.
2. e/m = 1.76 × 10¹¹ C/kg.
3. the value of e/m is independent of the nature of the material/metal used as the cathode (emitter), or the gas introduced in the discharge tube. This observation suggested the universality of the cathode ray particles.