Rutherford Scattering  (Aluminium Foil, Leybold)

The Rutherford scattering experiment is a classic experiment that revealed the structure of the atomic nucleus. In the version using a thin layer of aluminum 6 micro meters thick, alpha particles are fired towards the layer. Detectors are placed around the target to observe the scattering angle of the alpha particles. Most of the alpha particles penetrated the layer without any directional deviation, but a small portion underwent a large deflection, and were even reflected back. This result shows that most of the atomic volume is empty, and the positive charge and mass are concentrated in the very small and dense atomic nucleus. Using aluminum (Z = 13) as a target gave lighter scattering results than gold (Z = 79), but the basic principle remained the same - reinforcing the Rutherford atomic model that replaced the Thomson atomic model.