Atomic Theory Timeline

  • 330


    Rejected the idea of atoms.
    Stated that elements are made up of Fire, Water, Air, and Earth.
    Born in 384 B.C.
    Born in Stagira, Greece
  • Period: 330 to

    Atomic Theory

  • 450

    Democritus::The Atom

    Democritus::The Atom
    Democritus discovered the atom.
    He states that matter is destroyed when atoms seperate.
    Atoms are the smallest particles.
    Born in 460 B.C.
    Born in Abdera, Thrace
  • Antoine Lavoisier::Law of Conservation of Mass

    Antoine Lavoisier::Law of Conservation of Mass
    Law of Conservation of Mass--states that the mass of substances will remain constant no matter what processes it will go through.
    Burning Chemical Experiment
    Born in 1743
    Born in France
    Invented the balance
    Discovered respiration
  • Joseph Proust::Law of Definite Proportion

    Joseph Proust::Law of Definite Proportion
    Definite Proportion--a chemical compound always contains the same proportions of elements.
    Born in 1754
    Born in Angers, France
    Was a Chemical Analist
  • John Dalton::Atomic Theory

    John Dalton::Atomic Theory
    Developed the framework of an atom.
    The Atomic Theory--
    -All elements are made of small indivisible particles called atoms.
    -All atoms of the same element are the same.
    -Atoms are not created, destroyed or made into other kinds of atoms during chemical reactions. They are just rearranged into new compounds.
    -Compounds result from the chemical combination of a specific atoms of different elements. -Born in 1766
    -Born in Cumberland, England
    -Was a Meteorologist
  • J.J. Thomson::Electrons

    J.J. Thomson::Electrons
    Cathode Ray Experiment-Discovered electrons through deflection of rays using elecrically charged plates and magnets.
    -Born in 1856
    -Born in Manchester
    -Conducted his eperiment in 1897
  • Robert Millikan::Oil Drop Experiment

    Robert Millikan::Oil Drop Experiment
    -Discovered mass and voltage of electrons.
    -Oil Drop Experiment -Born in 1868
    -Born in Illinosis, United States
    -Conducted his experiment 1909
  • Ernest Rutherford::Nucleus

    Ernest Rutherford::Nucleus
    -Gold Foil Experiment -Born in 1871
    -Born in New Zealand
    -Discovered nucleus
  • Neils Bohr::Energy Levels

    Neils Bohr::Energy Levels
    -Light Experiment
    -Discovered Energy Levels -Born in 1885
    -Born Coperhagen