As part of an experiment with x-rays in 1909, Rutherford was shooting a beam of alpha particles (or alpha ... But every now and then, a particle bounced back as though it had hit something solid.

Ernest Rutherford ... dislodging a single particle. The particle had a positive charge, so it must have come from nucleus: he called this new particle a proton. With this experiment, he was ...

for which he received the Nobel Prize in Physics in 1922 Rutherford’s most famous experiment involved bombarding a thin sheet of gold foil with alpha particles. The unexpected results revealed ...