How does Rutherford atomic model differ from Thomson's?

1 Answer
Oct 22, 2014

Rutherford made an amazing discovery about the atom. Before his experiment it was presumed that all of the stuff inside of an atom was distributed in a uniform structure. Rutherford used a very thin gold foil which he bombarded with alpha particles. The gold foil was only a few atoms thick. It was expected that the alpha particles would punch through with just a little energy loss. Most of them did. But a few bounced back. It was described being like "shooting a cannon ball at a piece of tissue and having the cannon ball bounce back."

This revealed that some part (or parts) of the atom must be incredibly dense. We now understand that the nucleus of the atom contains most of the mass and has a diameter that is much smaller than the atom. For most atoms the nucleus is about 100,000 times smaller than the size of the atom. Most of the atom is empty space with a cloud of electrons buzzing around.