A piece of gold foil was hit with alpha particles, which have a positive charge. Most alpha particles went right through. This showed that the gold atoms were mostly empty space. Some particles had their paths bent at large angles. A few even bounced backward. The only way this would happen was if the atom had a small, heavy region of positive charge inside it.

-Realized positive charge was located in the nucleus of an atom

-He stated that electrons revolve around the nucleus in a circular path, but particles in motion would undergo acceleration and cause energy radiation.

-Proposed stable electron orbits and explained the emission spectra of some elements.

-Moving electrons should emit energy and collapse into the nucleus, and his model did not work well for heavy atoms.

Levels–Sublevels–Orbital

-Show´s electrons don't move around the nucleus in orbits, but in clouds where their position is uncertain.

-Still widely accepted as the most accurate model of the atom.