Atom/plum pudding

This model of the atom was made after the discovery of the Electron but before the discovery of the Proton or Neutron. In it, the atom is envisioned as electrons surrounded by a soup of positive charge, like plums surrounded by pudding. This model was disproven by an experiement by Earnest Rutherford when he discovered the nucleus of the atom.

see: Rutherford scattering