Rutherford’s scattering experiment  Hans Geiger and Ernest Marsden performed an experiment in which they fired alpha particles at a thin gold foil  Most of the alpha particles passed through with no or very small deflections in a vacuum, however, about 1 in 8000 was deflected through angles greater than 90 degrees  Rutherford proposed that the only way that the alpha particles were deflected in those large angles was if all the atom’s positive charge and nearly all its mass was concentrated in a small dense nucleus with electrons some distance away. Most of the atom is empty space.