Ernest Rutherford a New Zealander, studied under J. J. Thomson at the Cavendish Laboratory in England. He was the first scientist to propose the theory of the nuclear atom. His expirement, shown to the right, proves that "uranium emanations were shown to consist of three types of rays, alpha (helium nuclei) of low penetrating power, beta (electrons), and gamma, of exceedingly short wavelength and great energy."

Basically, he proved that the atom had a nucleus.

This is a sketch of Rutherford's expirement.