Electron Discovery and Properties of Cathode Rays

Study Notes

The electron was discovered through studies of electricity passage through gases at extremely low pressures in a gas-discharge tube experiment.
Applying a high voltage (>10,000 volts) across electrodes produces invisible rays, known as cathode rays, that move from the negative electrode to the positive electrode.

Cathode rays travel in a straight path from the cathode with high velocity.
They produce a shadow of an object placed in their path.
Cathode rays produce mechanical effects, such as rotating a small pedal wheel placed between the electrodes.
They are deflected by electric and magnetic fields, confirming they consist of charged particles.
Cathode rays produce X-rays when striking hard metals like tungsten, copper, etc.
They heat up thin metal foils when striking them.
Cathode rays produce a green glow when striking the glass wall beyond the anode.
They emit light when striking a zinc sulphide screen.
Cathode rays penetrate through thin sheets of aluminium and other metals.
They affect photographic plates.

The ratio of charge to mass (charge/mass) is the same for all cathode rays, regardless of the gas used in the tube.

The electron was discovered through studies of electricity passage through gases at extremely low pressures in a gas-discharge tube experiment.
Applying a high voltage (>10,000 volts) across electrodes produces invisible rays, known as cathode rays, that move from the negative electrode to the positive electrode.

Cathode rays travel in a straight path from the cathode with high velocity.
They produce a shadow of an object placed in their path.
Cathode rays produce mechanical effects, such as rotating a small pedal wheel placed between the electrodes.
They are deflected by electric and magnetic fields, confirming they consist of charged particles.
Cathode rays produce X-rays when striking hard metals like tungsten, copper, etc.
They heat up thin metal foils when striking them.
Cathode rays produce a green glow when striking the glass wall beyond the anode.
They emit light when striking a zinc sulphide screen.
Cathode rays penetrate through thin sheets of aluminium and other metals.
They affect photographic plates.