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Anode Ray Experiment

→Anode ray experiment was conducted by E Goldstein.

→These rays are also known as canal rays.

→This experiment helped in the discovery of the proton.


Apparatus Used

  • A discharge tube was taken in which there were 2 electrodes i.e. Anode(+ve) and the cathode (-ve).
  • The tube was filled with an inert gas.
  • A perforated or porous cathode was used.

  • A layer of zinc sulphide was placed at the back of the cathode.
  • There was a vacuum pump in the tube.
  • High voltage (5000v-10000v) was allowed to flow through the system.
  • It was observed that when the gas was at 1atm(atmospheric pressure) no change was seen in the tube. 
  • When the pressure was decreased inside the tube, a glow could be seen at the back side of the cathode.




Properties of Anode Rays

Properties of Anode Rays were similar to that of Cathode rays:
  1. Anode Rays rotates the paddle wheel.
  2. Anode Rays caused a heating effect.
  3. Anode Rays created a sharp shadow showing that they move in a straight line.
  4. Anode Rays were deflected towards the negative plate showing that particles are positively charged.



Conclusion

  • Anode rays were found to contain positively charged particle which was named as the proton.
  • The mass of proton was found as 1.67*10^ -27 kg.
  • The charge of proton was found as +1.6*10^-19 C