larry au's-atomic tmeline

By jaromau
  • 460

    460 B.C Democritus

    460 B.C Democritus
    460 B.C., did a Greek philosopher, Democritus, develop the idea of atoms
  • Period: Nov 5, 1000 to

    atomic timeline

  • Isaac Newton

    Isaac Newton
    Proposed a mechanical universe with small solid masses in motion.
  • Dalton Model

    Dalton Model
    John Dalton is usually credited with developing the first coherent atomic theory.
    Dalton's theory can be summarized as follows:
    -Matter is composed of small particles called atoms.
    All atoms of an element are identical, but are different from those of any other element.
    -During chemical reactions, atoms are neither created nor destroyed, but are simply rearranged.
    -Atoms always combine in whole number multiples of each other.
  • J. Plucker

    J. Plucker
    Built one of the first gas discharge tubes ("cathode ray tube").
  • James Clerk Maxwell

    James Clerk Maxwell
    Proposed electric and magnetic fields filled the void.
  • E. Goldstein

    E. Goldstein
    Used a CRT to study "canal rays" which had electrical and magnetic properties opposite of an electron.
  • English physicist J.J. Thomson

    English physicist J.J. Thomson
    the electron and proposed a model for the structure of the atom. Thomson knew that electrons had a negative charge and thought that matter must have a positive charge.
  • Max Planck

    Max Planck
    In 1900 Max Planck, a professor of theoretical physics in Berlin showed that when you vibrate atoms strong enough, such as when you heat an object until it glows, you can measure the energy only in discrete units. He called these energy packets, quanta.
  • Abegg

    Discovered that inert gases had a stable electron configuration which lead to their chemical inactivity.
  • Gold Foil Experiment

    Gold Foil Experiment
    Ernest Rutherford
    He discovered the existence of the atomic nucleus. He discovered this by using the Gold Foil Experiment or the Rutherford Experiment.
  • Niels Bohr

    Niels Bohr
    In 1912 a Danish physicist, Niels Bohr
    RULE 1: Electrons can orbit only at certain allowed distances from the nucleus.
    RULE 2: Atoms radiate energy when an electron jumps from a higher-energy orbit to a lower-energy orbit. Also, an atom absorbs energy when an electron gets boosted from a low-energy orbit to a high-energy orbit.
  • Rutherford

    Not until 1919 did Rutherford finally identify the particles of the nucleus as discrete positive charges of matter. Using alpha particles as bullets, Rutherford knocked hydrogen nuclei out of atoms of six elements: boron, fluorine, sodium, aluminum, phosphorus, an nitrogen. He named them protons, from the Greek for 'first', for they consisted of the first identified building blocks of the nuclei of all elements. He found the protons mass at 1,836 times as great as the mass of the electron.
  • Aston

    Discovered the existence of isotopes through the use of a mass spectrograph.
  • Louis de Broglie

    Louis de Broglie
    In 1924 a Frenchman named Louis de Broglie thought about particles of matter. He thought that if light can exist as both particles and waves. he showed what matter waves would behave like if they existed at all
  • Max Born

    Max Born
    In 1926, a German physicist, Max Born had an idea about 'psi'
  • James Chadwick

    James Chadwick
    1932 did the English physicist James Chadwick finally discover the neutron. He found it to measure slightly heavier than the proton with a mass of 1840 electrons and with no charge (neutral). The proton-neutron together, received the name, "nucleon."
  • Werner Heisenberg

    Werner Heisenberg
    Werner Heisenberg concluded that charged particles bounce photons of light back and forth between them.
  • Enrico Fermi

    Enrico Fermi
    Conducted the first controlled chain reaction releasing energy from the atoms nucleus.