Ernest Rutherford
Ernest Rutherford and his colleagues performed an experiment, it is called the Alpha scattering experiment, it was tedious and very time consuming. The experiment was to study how alpha particles interact with thin metal foils. Rutherford aimed a beam of high speed alpha particles at very thin gold foil, almost all the particles passed through with no deflection. Rutherford and his colleagues found that the foil scattered alpha particles in all directions. J.J. Thomson’s model was the ‘plum-pudding’ experiment and Rutherford looked over Thomson’s experiment and said it was all wrong. Rutherford’s observations led him to conclude that Thomson’s model is wrong and Rutherford proposed that all of an atoms positive charge and most mass are concentrated into a very small core at the atoms center (nucleus).