How will you prove that electrons are negatively charged particles with a definite mass?

Explanation

Under the influence of an electric field the cathode rays as well as the electron beam, are deflected towards the positive plate of the electric field. Cathode rays also neutralise the gold leaf electroscope, charged with positive electricity. Thus it can be proved that electrons are negatively charged. al light paddle wheel placed in the path of cathode rays, begins to rotate, showing that cathode rays are made of matter particles.