Electron Discovery and Properties of Cathode Rays

Electron Discovery and Cathode Rays

• 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.

Properties of Cathode Rays

• 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.

Charge-to-Mass Ratio of Cathode Rays

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

Electron Discovery and Cathode Rays

• 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.

Properties of Cathode Rays

• 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.

Charge-to-Mass Ratio of Cathode Rays

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

Learn about the discovery of electrons through gas-discharge tube experiments and the properties of cathode rays, including their velocity and path.