The Atom Timeline

  • Dalton: Solid Sphere Model

    The Solid Sphere Model was the first atomic model and was developed by John Dalton. He hypothesised that an atom is a solid sphere that could not be divided into smaller particles.
  • Thompson: The Plum Pudding Model

    Thomson proposed the plum pudding model of the atom, which had negatively-charged electrons embedded within a positively-charged "soup."
  • Rutherford: The Nuclear Model

    Rutherford was the first to determine the presence of a nucleus in an atom. He bombarded α-particles on a gold sheet, which made him encounter the presence of positively charged specie inside the atom.
  • Bohr: The Bohr (Planetary) Model

    The Bohr Model is a structural model of an atom. The Bohr model was an advancement to an earlier atomic model, the Rutherford Model.
  • Schrodinger: Quantum Mechanics Model

    Erwin Schrödinger, took the Bohr atom model one step further. Schrödinger used mathematical equations to describe the likelihood of finding an electron in a certain position. This atomic model is known as the quantum mechanical model of the atom.
  • Today's date