Physics – 5.1.1 The atom | e-Consult

When alpha particles are directed towards a thin metal sheet, they are scattered in various directions. The fact that only a small fraction of the alpha particles experience a head-on collision with a proton in the nucleus explains the large scattering angle observed. This indicates that the alpha particles are passing through a vast amount of empty space. The small size of the nucleus, compared to the overall size of the atom, is crucial for this scattering pattern. If the nucleus were large, the alpha particles would be more likely to collide with protons before passing through.

• The large scattering angles observed are not explained if the positive charge were concentrated in a small area.
• The low probability of head-on collisions suggests a significant void within the atom.