Scattering Experiment

5. "Shells off Tissue Paper"

A few days after Marsden had been asked to look for alpha particle scattering at large angles, Geiger came back to Rutherford very excited. They had been able to get scattering at very large angles, some even appearing to bounce right back at the source of the particles!

Rutherford described it as the most incredible event of his life, "as if you fired a 15-inch shell at a piece of tissue paper and it came back and hit you."

Such huge deflections could not be explained by Thomson's model of the atom, where charge was distributed evenly throughout the atom. For such large deflections all the positive charge had to be concentrated in a small mass greater than the mass of the alpha particles.

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