Ernest Rutherford
Performed Gold Foil Experiment
What the gold foil experiment was
Alpha particles were shot in a beam form through a gold foil sheet that was one atom thick. Most of the time, the particles went straight through. But rarely, a particle would bounce in a different direction. When the particle went though, it went between the nucleus and the electrons. When the bounced off, the particle hit the nucleus.
What was determined from the Experiment?
Rutherford determined that the space in an atom is mostly empty, given the particles mostly went through. He also determined that the size of the atom is relatively small with in the atom, for the particles would rarely bounce off it.