Rutherford's atomic structure model was revolutionary. Contrary to J.J. Thompson's "plum pudding" model (which consisted of a solid, even mixture of protons and electrons), Rutherford's model consisted of one small, positively charged, dense nucleus, a layer of empty space, and a layer of negatively charged electrons. He came to this conclusion through his gold-foil experiment. He shot a ray of alpha particles towards the thin gold foil, and to Rutherford's surprise, some of the rays reflected back instead of going straight through the foil as he originally thought.
