Principle of Rutherford’s experiment
By bombarding a very thin gold foil with alpha particles, Hans Geiger and Ernest Marsden, both students of Rutherford, observed that a small fraction (1 in 8000) of these particles were deflected at large angle as if it bounced off a heavy obstacle. The impacts were observed as scintillations in the dark, under the microscope, on a screen of zinc sulphide. Rutherford concluded that the atom contained a heavy heart, with positive electric charge, able to push away the alpha