This experiment proved that atoms are not massive, they have large blanks inside the structure. Therefore, models like Thomsom's and Dalton's weren't good enough to describe the comportment of these units. A model of an atom like a <em>planetary system</em> was elaborated after this.
Rutherford performed the gold foil experiment and the observation was as follows:
Most of the alpha particles passed undeflected through the atom proving that most of the atom is empty space.
A certain fraction of alpha particles deflected by 90 degrees that indicated the center of the atom is positive.
Another small fraction of alpha particles deflected by more than 90 degrees that indicated that most of the atom's mass lies in a small volume at the center of the atom.
