CBSE Class 9 Answered

Discovery of the Proton

• A German scientist, E. Goldstein in 1886, modified the discharge tube and passed an electric current through it.
• He found that the positively charged rays were emitted from the anode in the discharge tube. These rays were called canal rays.

• When an electric field was applied, these rays deflected towards the negatively charged plate. Thus, Goldstein concluded that an atom contains positively charged particles along with the electrons.
• These positively charged particles were named as protons by a British scientist, Ernest Rutherford.
• Canal rays were also called anode rays since they were emitted from anode (electrode connected to the positive terminal of high voltage source) in the gas discharge experiments using a perforated cathode.