Atomic Theory Timeline

  • 221

    Great Wall Of China

    During the Qin Dynasty, construction of the Great Wall of China begins.
  • 276

    Eratosthenes Measure the Earth's Circumference

    or so he thought.
  • 300

    Democritus

    Democritus
    Said that if you cut something in half again and again, there will come a point that you cannot cut it in half anymore. He said that it was invisible, which in greek is atomos. Thus, the theory of the atom was born.
  • 300

    Aristotle

    Aristotle
    Beleived that everything in the univers was made up of four elements. Air, Fire, Earth and Wind.
  • 300

    Invisible Model

    Democritus thought that the atom was an invisible force that held everything togeather.
  • Dec 18, 610

    Muhammad

    Muhammad
    Begins preaching in Mecca
  • Dec 18, 1180

    First Windmill

    First Windmill
    Was constructed in Norway
  • Dec 18, 1492

    Columbus

    Columbus
    He indeed discovered America
  • Isaac Newton

    Isaac Newton
    Came up with the idea of small solid masses in motion in a mechanical universe.
  • Rudjer Josip Boscovic

    Rudjer Josip Boscovic
    Internal spatial coordinates are used instead of external coordinates. Boscovich's theory is kinematic rather than dynamical. It uses only two-dimensional quantities rather than the three used by Newton.
  • Joseph Priestly

    Joseph Priestly
    Best known for his discovery of oxygen (i giggled a little at that one) he was able to isolate it and identify it.
  • Great Britain and Ireland

    Merged to become the United Kingdom
  • John Dalton

    John Dalton
    Atoms are the smalles part of the element. Atoms of the same element have the same atomic mass. The ratio of the masses of the bonded elementes will always be a definite whole-number proportion.
  • Small, Spherical,Solid Model

    Small, Spherical,Solid Model
    Developed by Dalton. Thought that the atom was shaped like this.
  • Antarctica was discovered

  • Michael Faraday

    Michael Faraday
    Studied the effect of electricity on solution, coined term "electrolysis" as splitting molecules with electrisity, developed laws of electrolysis. Faraday himself was not a proponent of atomism.
  • First telegraph

    line was connected in the world between Baltimore and Washington
  • J. Plucker

    J. Plucker
    Built one of the first gas discharge tubes. Also known as a Cathode Ray Tube.
  • Asprin was discovered

  • First commercial film was released

  • Wilhelm Roentgen

    Wilhelm Roentgen
    Discovered X-rays
  • Henri Becquerel

    Henri Becquerel
    Found that if uranium was left on a photographic plate without any light, the ore would leave an image.
  • Olympic Games revived in Greece

  • JJ Thomson

    JJ Thomson
    Discovered the electron, and put forward a theory that the atom was made up of smaller particles. He proved this theory using the cathode ray tube.
  • Plum Pudding Model

    Plum Pudding Model
    J.J. Thompson developed this model. He described the atom to be a mixture of positivly and negativly charged particles mixted togeather.
  • Soddy

    Soddy
    Observed spontaneous disintegration of radioactive elements into variants he called "isotopes" or totally new elements, discovered "half-life", made initial calculations on energy released during decay.
  • Marie Curie

    Marie Curie
    discovered new elements and conducted radiation test to understand how the elements reacted.
  • Russia Japan War

  • Ethiopia decleared independence

  • Sicily earthquake kills tens of thousands

  • Ernest Rutherford

    Ernest Rutherford
    Discovered the atom to be made up of a positive, solid core and an orbiting mass of electrons and neutrons. He did so by experimenting with a gold foil and an infinite particle emitter.
  • Niels Bohr

    Niels Bohr
    His atomic theory was a combo of Rutherford's work and Planck's Quantom theory. Bohr proposed that the outer orbits could accommodate more electrons than the inner orbits
  • Planetary Model

    Planetary Model
    Neils Bohr founded the model, he thought that the electrons orbited the positivly charged nucleus like the planets orbit the sun.
  • Irish free state established

  • Werner Heisenberg

    Werner Heisenberg
    Invented matrix mechanics, the first version of quantom mechanics. He extended this to complete a mathimatical theory of the behavior of atoms and their constituents.
  • Electron Cloud Model

    Electron Cloud Model
    Werner Heisenberg found that the electrons just occupy a general area of space around the central positive nucleus.
  • Erwin Schrodinger

    Erwin Schrodinger
    Set a foundation for wave-mechanics approch to quantum theory.
  • New York stock market crash

  • James Chadwick

    James Chadwick
    Provided the existance of neutons as uncharged particles in atoms.
  • NATO established

  • Robert Millikan

    Robert Millikan
    Discovered the charge on an electron during the Oil Drop Experiment
  • The Social War

    Revolt of the Italians who wanted Roman Citizenship.
  • Social War

    Revolt of Italians who wanted Roman Citizenship
  • World Trade Center Towers Collapsed

  • Barack Oboma Elected president of the US

  • Gunman assults Conn. elementary school, 27 dead