History of the Atom Timeline by Kaleb Pierson

By kp_pierson
  • 450

    Democritus

    Democritus
    Discovered in: 400 B.C
    Discovered that: The atom was enternal and so small it was considered invisible,
    Method: Used experiments and asked questions.
  • 450

    Aristotle

    Aristotle
    Discovered in: 340 B.C
    Discovered that: Everything wasnt just made of the four elements
    Method: theory
    Citation: http://the-history-of-the-atom.wikispaces.com/Aristotle

  • Dalton

    Dalton
    Discovered in:1803
    Discovered that: all atoms of a given element are identical in mass and properties, a chemical reaction is a rearranging of atoms,compounds are formed by a combinations of 2 or more different attoms.
    Method: theory
    Citation: http://www.rsc.org/chemsoc/timeline/pages/1803.html

  • Thompson

    Thompson
    Discovered in: 1897
    Discovered that: Atoms consist of a sphere of posotive charge with negative charged electrons in it, discovered electrons,
    Method: series of experiments
    Name for his model: plum pudding model
    Citation: http://www.tutorvista.com/science/thomsons-atomic-theory

  • Rutherford

    Rutherford
    Discovered in: 1911
    Discovered that:Atoms have posotive nucleus in the center and negative orbating electrons.
    Method: Gold foil experiment
    Citation: http://www.rsc.org/chemsoc/timeline/pages/1911.html

  • Bohr

    Bohr
    Discovered in: 1913
    Discovered that: electrons travel in stationary orbits by their angular momentum but he was wrong because if the electrons were orbiting in a curved path, they would lose energy and spiral into the nucleus.
    Method: quantized shell modell
    Citation: http://www.rsc.org/chemsoc/timeline/pages/1913.html

  • Heisenberg and Schrodinger

    Heisenberg and Schrodinger
    Discovered in: 1926-1927
    Discovered that: the exact path cant be predicted
    Method: mathematical quantities