Discovery of the Atom

  • Solid Sphere model

    First atomic model. Hypothesized an atom is a solid sphere and can not bedivided smaller
  • Plum Pudding model

    the atom is composed of electrons surrounded by a soup of positive charge to balance the electrons' negative charges
  • Nuclear model

    the protons and neutrons, which comprise nearly all of the mass of the atom, are located in the nucleus at the center of the atom. The electrons are distributed around the nucleus and occupy most of the volume of the atom
  • Bohr model

    shows that the electrons in atoms are in orbits of differing energy around the nucleus (think of planets orbiting around the sun). Bohr used the term energy levels (or shells) to describe these orbits of differing energy. ... The energy level an electron normally occupies is called its ground state.
  • quantum mechanics model

    treats electrons as matter waves. ... An atomic orbital is defined as the region within an atom that encloses where the electron is likely to be 90% of the time.
  • today