Rutherford made the following conclusions based on the two major observations from the gold-foil experiment. Please note that other metal foils were also used. The results from each metal foil were the same, indicating that all atoms in nature have a similar atomic structure.
Observation #1: Most of the alpha particles passed directly through the gold foil.
Conclusion #1: The atom must consist of mostly empty space.
Observation #2: Some of the positive alpha particles were deflected at large angles and some came directly back to the source of the radiation.
Conclusion #2: The atom must contain a small, dense, positive center.
This positive center of the atom is referred to as the nucleus and it must be considerably smaller than the total size of the atom; otherwise, the scientists would have observed a greater amount of scattering of the alpha particles. The nucleus must be more massive than the incoming alpha particles in order to cause the alpha particles to be deflected at such large angles and directly backward. Also, the nucleus must be positively charged since the particles had no interaction with the nucleus; in other words, if the nucleus was negative, the alpha particles could experience an attraction if the charges were opposite. However, since the particles were repelled from the small dense nucleus, the overall charge of this body must be positive.
