Rutherford Scattering

Discover the nuclear model of the atom through alpha particle scattering

In 1909, Geiger and Marsden fired alpha particles at gold foil. Most passed through, but a few scattered at large angles — even backward. This contradicted the Thomson 'plum pudding' model and led Rutherford to propose the nuclear model: nearly all atomic mass is concentrated in a tiny, positively-charged nucleus. The scattering angle depends on how close the alpha particle passes to the nucleus, governed by Coulomb repulsion.