How did Rutherford's gold foil experiment work?
We directed a beam of alpha particles, which are positively charged helium nuclei, at a very thin sheet of gold foil. Most particles passed straight through, indicating that matter is mostly empty space. However, a small fraction were deflected at large angles, and some even bounced back. This unexpected scattering could only be explained by a concentrated positive charge and mass within the atom – the nucleus.
Ask Ernest Rutherford the follow-up →