2- Gold Foil Experiment

1) Ernest Rutherford, 1905. Directed a beam of (+charge)alpha particles at v. thin gold foil 2) Did this in a suspended vacuum ∴ any deflection of alpha particles would be due to collisions with the gold foil. 3) Most particles went straight through ∴ most of an atom is empty space 4) A few deflected by large angles (>4°) ∴ concentration of +charge in the atom (like charges repel) 5) Very few came straight back ∴ + charge and mass concentrated in a small volume (nucleus)