CPB Budapest 2017

Ernest Rutherford (1871-1937) and his group in 1911 disproved the Thomson’s atom model in a series of scatter experiments using alpha particles and gold foils. He was surprised to discover that the largest portion of the incident alpha particles was able to penetrate the foil having Atoms: Rutherford ´ s Atom Model been only slightly deflected. Only a small portion were scattered at large angles. According to these results, Rutherford suggested that the positive atomic charge and almost all the atomic mass is concentrated in a very small central body with a diameter of some femtometers (1 fm = 10 -15 m) instead of being distributed over the whole volume of the atom with a diameter of about 0.1nm. Originally Rutherford ignored the sign of the charge of the nucleus, since as he pointed out, the angular distribution of the scattered alpha particles is independent of the sign of the nuclear charge.