History of the Atomic Theory

By Symonso
  • 350 BCE

    Aristotle

    Aristotle
    Aristotle disagreed with Democritus' model of the atom. Aristotle ideas were more scientifically based, making him disagree even more with Democritus' ideas. Aristotle did not have an atomic model due to the fact that he thought atoms did not exist.
  • 450

    Democritus

    Democritus
    Democritus was the first person to create a model of the atom. He was the first person to discover that all matter is made up of invisible particles called atoms, and also discovered that atoms are solid, indestructable and unique. However, he did not know about a nucleus or electrons, he just knew that everything was made of atoms.

  • Antoine Lavoisier

    Antoine Lavoisier
    Lavoisier was a Frenchman that founded several elements and he put together the first table of elements.

  • Dalton

    Dalton
    Dalton was the first scientist to be able to explain the behaviour of atoms in terms of the measurement and weight. Dalton proposed an additional "rule of greatest simplicity" that created controversy, since it could not be independently confirmed.

  • J.J Thomson

    J.J Thomson
    J.J Thompson was a very important scientist. Up until his discovery, all models of the atom looked like a big solid ball. Thomson discovered the electron, which led him to creating the "plum pudding model."

  • Rutherford

    Rutherford
    Rutherford was another scientist who changed the atomic model, because he believed that J.J Thomson was wrong. He created the nucleus and said that instead of the positive matter being the whole atom, it was just in the middle. He said the atom was mostly empty space and that electrons surrounded the positive nucleus.

  • Bohr

    Bohr
    Bohr was a Danish student of Rutherford's, and he decided to make a new model based off of Rutherford's model, but change the orbit of the electron. He also created and discovered energy levels in the atom.

  • Schrodinger

    Schrodinger
    Schrodinger was a scientist who disagreed with Bohr's ideas and creations, so he made his own atomic model. He thought that the only way to find the location and energy of an electron in an atom was to calculate its probability of being a certain distance from the nucleus