In the year 1898 Thomson created the idea of atom as the positive charged ball in which there are negative charges placed - the "plum cake" model. So summing up whole a atom were to be neutral the In the years 1909-1911 Ernest Rutherford and his students - Hans Geiger (1882-1945) and Ernest Marsden conducted some experiments to search the problem of alpha particles scattering by the thin gold-leaf. Rutherford knew that the particles contain the 2…showed first 75 words of 583 total…

…showed last 75 words of 583 total…would mean that the alpha particle would be deflected less than expected. So, he hypothesised that if the alpha particles were penetrating the nucleus, the number being deflected by large angles would be less than predicted. However, the experiment revealed no such deviation, meaning that the alpha particles were not penetrating the nucleus. And therefore, he concluded that the nucleus must be smaller than the distance of closest approach of any of the alpha particles