Chemistry
With reference to the discovery of the structure of an atom, explain in brief - William Crookes experiment for the discovery of cathode rays, followed by - J.J. Thomsons experiment pertaining to the constituents of the cathode rays.
State which sub-atomic particle was discovered from his experiment.
Answer
William Crookes Experiment:
William Crookes passed an electric discharge through a discharge tube containing a gas at low pressure. Blue rays were emitted from the cathode [negative plate] which were called cathode rays.
J.J. Thompson's Experiment:
In his experiments, J.J. Thomson studied the characteristics and constituents of cathode rays and observed that the rays have kinetic energy & cast a shadow of an object in their path. They were deflected by a positively charged plate.
Discovery of electron:
This proved that the cathode rays consisted of negatively charged sub-atomic particles called electrons.
Related Questions
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Draw a neat labeled diagram representing an atom. Name the three sub-atomic particles in the atom & represent them symbolically showing the mass & charge of each. State where the sub-atomic particles are present in the atom.
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