Z

THE ATOMIC THEORY TIMELINE

By grikayla
  • 105

    Greeks

    Greeks
    The Greeks discovered that matter can be divided, and that sooner or later, there has to be a point where it can't be divided any farther. Picture Source:http://www.greekmyths-greekmythology.com/wp-content/uploads/2009/07/Greece-Ancient_11736735-300x225.jpg
  • 200

    Aristotle 332 BCE

    Aristotle 332 BCE
    Aristotle disbelieved the ancient Greek theory of atoms being of different sizes, regular geometric shapes and beig in constant motion.
  • 400

    Democritus (400 B.C.)

    Democritus (400 B.C.)
    He found that all matter is made of atoms, that atoms are invisible to the naked eye, and that they are industructable.

  • Ernest Rutherford (1871 – 1937)

    Ernest Rutherford (1871 – 1937)
    In 1899 Ernest Rutherford conducted an experiment where he used alpha particles to study the nature of atomic structure.He used the alpha particles as nucleur bullets to smash the atoms to see them burst. Instead of finding bit and peices of atoms, he found that a small portion of the alpha particles were deflected, when another section bounced back.

  • Niels Bohr (1885-1965)

    Niels Bohr (1885-1965)
    The model to the side shows how Bohr pictured the atom.

  • Wolfgang Pauli (1900-1958)

    Wolfgang Pauli (1900-1958)
    He wondered if the electron could spin around its axis as it orbited the nucleus just like the earth revolves around the sun.

  • James Chadwick (1891-1974)

    James Chadwick (1891-1974)
    James predicted the atom would have a neutron, he established that atomic number is determined by the numbers of protons in an atom, and he also discovered the fourth the neutron.

  • Electron Cloud Model

    Electron Cloud Model
    The Electron Cloud Model is a model based off of the many theories of Werner Heisenberg. Basically, it says that the location of a particle cannot be known. Therefore, we cannot exactly know where an electron will be.