1. Introduction

Discovery of Electrons – Cathode Rays (By J. J. Thomson)

→ Thomson explained presence of electrons by cathode rays experiment.

Facts about Electrons

→ Charge on electron = −1.6 × 10^-19 C (C = Coloumb)

(As calculated by Robert E. Millikan)

→ Mass of electron = 9.1 × 10^-31 kg