Page 1 - 3. LESSON NOTES-(CONCEPT OF CATHODE AND ANODE RAYS)
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SAI International School
                                                       Class-IX

                                                Subject- Chemistry
                                             Topic-Structure of atom

                              Subtopic- Concept of Cathode and anode rays
                                    Concept of Cathode and Anode Rays
                                                   Lesson Notes


               Cathode ray experiment


                     J. J. Thomson discovered the existence of electrons.

                     He did this using a cathode ray tube, which is a vacuum-sealed tube with
                       a cathode and anode on one end that created a beam of electrons travelling towards
                       the other end of the tube.

                     The air inside the chamber is subjected to high voltage and electricity flows through
                       the air from the negative electrode to the positive electrode.

                     The characteristics of cathode rays (electrons) do not depend upon the material of
                       electrodes and the nature of the gas present in the cathode ray tube.
                     The experiment showed that the atom was not a simple, indivisible particle and
                       contained at least one subatomic particle – the electron.

















               Properties of cathode rays:

                     They travel linearly.
                     They have a negative electric charge.
                     They have particle property.
                     Magnets can deflect them.
                     Charge/mass ratio of the rays is constant.
                     They travel from the cathode to the anode.
                     Their properties are independent from the electrodes and gas present in the cathode
                       ray tube.




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