How can we prove that the electrons carry negative charge?
J.J. Thomson found that cathode rays were attracted by positively charge plate and repelled by the negatively charge plate. This led him to the conclusion that the cathode rays (electrons) were made up of negatively charge.
J. J. Thomson designed a glass tube that was partly evacuated, i.e. all the air had been drained out of the building. He then applied a high electric voltage at either end of the tube between two electrodes. He observed a particle stream (ray) coming out of the negatively charged electrode (cathode) to the positively charged electrode (anode). This ray is called a cathode ray and is called a cathode ray tube for the entire construction
Procedure of the Experiment
1. Apparatus is set up by providing a high voltage source and evacuating the air to maintain the low pressure inside the tube.
2. High voltage is passed to the two metal pieces to ionize the air and make it a conductor of electricity.
3. The electricity starts flowing as the circuit was complete.
4. To identify the constituents of the ray produced by applying a high voltage to the tube, the dipole was set up as an add-on in the experiment.
5. The positive pole and negative pole were kept on either side of the discharge ray.
6. When the dipoles were applied, the ray was repelled by the negative pole and it was deflected towards the positive pole.
7. This was further confirmed by placing the phosphorescent substance at the end of the discharge ray. It glows when hit by a discharge ray. By carefully observing the places where fluorescence was observed, it was noted that the deflections were on the positive side. So the constituents of the discharge tube were negatively charged.
Conclusion
After completing the experiment J.J. Thomson concluded that rays were and are basically negatively charged particles present or moving around in a set of a positive charge.
J.J. Thomson found that cathode rays were attracted by positively charge plate and repelled by the negatively charge plate. This led him to the conclusion that the cathode rays (electrons) were made up of negatively charge.
J. J. Thomson designed a glass tube that was partly evacuated, i.e. all the air had been drained out of the building. He then applied a high electric voltage at either end of the tube between two electrodes. He observed a particle stream (ray) coming out of the negatively charged electrode (cathode) to the positively charged electrode (anode). This ray is called a cathode ray and is called a cathode ray tube for the entire construction
Procedure of the Experiment
1. Apparatus is set up by providing a high voltage source and evacuating the air to maintain the low pressure inside the tube.
2. High voltage is passed to the two metal pieces to ionize the air and make it a conductor of electricity.
3. The electricity starts flowing as the circuit was complete.
4. To identify the constituents of the ray produced by applying a high voltage to the tube, the dipole was set up as an add-on in the experiment.
5. The positive pole and negative pole were kept on either side of the discharge ray.
6. When the dipoles were applied, the ray was repelled by the negative pole and it was deflected towards the positive pole.
7. This was further confirmed by placing the phosphorescent substance at the end of the discharge ray. It glows when hit by a discharge ray. By carefully observing the places where fluorescence was observed, it was noted that the deflections were on the positive side. So the constituents of the discharge tube were negatively charged.
Conclusion
