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Atomic Theory Timeline

  • Period: to

    John Dalton

    He mentioned that he believed that all matter had been made of atoms and that they could not be destroyed at all (discovery of the atom).
  • Pennsylvania abolishes slavery

    Pennsylvania abolishes slavery
    Pennsylvania became the first US state to abolish slavery but this only meant for the new-borns not the current slaves that they had.
  • Dalton's article for atomic weight

    Dalton's article for atomic weight
    In the year 1803 Dalton wrote an article for Machester Literary in which he was able to make a chart of the atomic weight of each element.
  • New York riot

    New York riot
    Riot breaks out in New York due to the increase in flower prices and because of the poverty within the area.
  • Period: to

    JJ Thomson

    Discovered the electron by performing several experiments that included what he called negatively charged particles, also known for the creation of the well known plum pudding model.
  • Period: to

    Ernest Rutherford

    Used his experiment called the gold foil experiment and at the same time said that in the center of every atom there is a positively charged core which he called the nucleus he also came up with the model which showed particles orbiting the nucleus.
  • Thomson becomes Cavendish Professor of Physics

    Thomson becomes Cavendish Professor of Physics
    Thomson gets the opportunity to be a Cavendish Professor teaching Physics.
  • Period: to

    Niels Bohr

    Bohr said that electrons orbit the nucleus and that they can only be in specific energy levels but sometimes can jump to other energy levels in the orbit.
  • Ernest discovers the nucleus

    Ernest discovers the nucleus
    (no specific month or day) Rutherford used his gold foil experiment eventually discovering that there must be something in the center od the atoms making them bounce away.
  • Post office delivers

    Post office delivers
    The post office finally starts delivering parcel mail to people which would be the mail item wrapped in paper and delivered to the person.
  • Bohr Model

    Bohr Model
    (no specific month or day) Bohr discovered that electrons orbit the nucleus and that they have specific energy levels in which they must be at.
  • Alcatraz

    Alcatraz
    Alcatraz officially opens and becomes a federal prison for mostly federal felony crimes.
  • Navy Seals established

    Navy Seals established
    The U.S. Navy Seals established within the lifetime of Bohr in the year that he died.