| Under the prevailing plum pudding model, the alpha particles should all have been deflected by, at most, a few degrees; measuring the pattern of scattered particles was expected to provide information about the distribution of within the atom | Although many of the alpha particles did pass through as expected, many others were deflected at small angles while others were reflected back to the alpha source |
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| It was then that I had the idea of an atom with a minute massive center, carrying a charge |
Rutherford's experiment consisted of a beam of , generated by the of , was directed normally onto a sheet of very thin foil in an evacuated chamber.
| It was almost as incredible as if you fired a 15-inch shell at a piece of tissue paper and it came back and hit you | series of experiments 1908-1913 by Hans Geiger and Ernest Marsden, directed by Ernest Rutherfofrd, at the University of Manchester, proving the existence fo the atomic nucleus through alpha particle scattering on gold foil |
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| However, the actual results surprised Rutherford | According to Rutherford: It was quite the most incredible event that has ever happened to me in my life |
On consideration, I realized that this scattering backward must be the result of a single collision, and when I made calculations I saw that it was impossible to get anything of that order of magnitude unless you took a system in which the greater part of the mass of the atom was concentrated in a minute nucleus.
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