History of the Atomic Theory

By deberry9
  • 460

    Democritus

    1. All matters consists of invisble particles called atoms
      1. Atoms are indestructible.
    2. Atoms are solid but invisible.
      1. Atoms are homogenous.
      2. Atoms differ in size, shape, mass, position, and arrangement. Solids are made of small, pointy atoms. Liquids are made of large, round atoms. Oils are made of very fine, small atoms that can easily slip past each other. He studied Pythagoreanism for a brief part of his life

  • Antoine Lavoisier

    Lavoisier was known for his experimentation skills. One of his favorite experiments being turning HgO into Hg+O. He used this experiment to help himself come up with the Law of Conservation. The law states that matter cannot be made or destroyed. He also hints at the rearrangement of matter in reactions. Matter rearranged, but never disappeared He was suspected of treason during the French Revolution

  • John Dalton

    Dalton's Theory. His theory contained 6 parts:
    matter is composed of extremely small particles called atoms
    atoms are indivisible and indestructable
    atoms of a given element are identical in size, mass, and chemical properties
    atoms of specific elements are different thatn those of other elements
    in a chemical reaction, atoms separate, combine and/or rearrange
    He was a quaker

  • Max Planck

    used the idea of quanta (discrete units of energy) to explain hot glowing matter he realized that light and other electromagnetic waves were emitted in discrete packets of energy
    Talented musician

  • Marie Curie

    discovery of radiation in uranium as her thesis topic, Curie began the systematic study of other elements to see if there were others that also emitted this strange energy. Within days she discovered that Therium also emitted radiation, and further, that the amount of radiation depended upon the amount of element present in the compound. Thus, she deduced that radioactivity does not depend on how atoms are arranged into molecules, but rather that it originates within the atoms themselves. This d

  • Robert Millikan

    The oil drop experiment attempt to measure the charge of an electron
    In 1923 he won the nobel peace prize

  • Ernest Rutherford

    Rutherford after many experiments came to the conclusion that the following were true:
    An alpha particle (α=He^+2) is positive
    A Beta particle (β=e-) is negative
    A neutral particle (ϒ) is light Rutherford's most famous experiment is the gold foil experiment. It consisted of shooting Alpha atoms into extremely thin gold foil and seeing where on the surrounding circular wall it hit. He believed they would all just go straight through. However, a very small amount went either off to the sides or

  • Albert Einstein

    In March 1905 , Einstein created the quantum theory of light, the idea that light exists as tiny packets, or particles, which he called photons. Alongside Max Planck's work on quanta of heat Einstein proposed one of the most shocking idea in twentieth century physics: we live in a quantum universe, one built out of tiny, discrete chunks of energy and matter.
    In 1907, he confronted the problem of gravitation. Einstein began his work with one crucial insight: gravity and acceleration are equivalen

  • Niels Bohr

    Bohr's greatest contribution to modern physics was the atomic model. The Bohr model shows the atom as a small, positively charged nucleus surrounded by orbiting electrons.

    The chemical element bohrium (Bh), No. 107 on the Periodic Table of the Elements, is named for him.

  • Erwin Schrodinger

    A powerful model of the atom was developed by Erwin Schrodinger in 1926. Schrodinger combined the equations for the behavior of waves with the de Broglie equation to generate a mathematical model for the distribution of electrons in an atom. The advantage of this model is that it consists of mathematical equations known as wave functions that satisfy the requirements placed on the behavior of electrons. The disadvantage is that it is difficult to imagine a physical model of electrons as waves.

  • James Chadwick

    James predicted the atom would have a neutron.
    He established that atomic number is determined by the numbers of protons in an atom.
    He also discovered the fourth subatomic particle, the neutron.
    1935 got the nobel peace prize

  • Louis de Broglie

    His ideas were a basis for developing the wave mechanics theory. This theory has greatly improved our knowledge of the physical nature on the atomic scale. He received the Nobel Prize for Physics on his wave nature of electrons discovery in 1929.
    He believed that electrons can act like both particles and waves, just like light. He also said that waves produced by electrons contained in the orbit around the nucleus, set up a standing wave of a certain energy, frequency, and wavelength. He discove

  • J.J. Thompson

    Thomson created the cathode ray. The cathode ray is a tube that when a high voltage current is sent through it and the atoms hit the outside of the tube it glows. In this way, Thomson was able to test the polarity of the atoms by placing a magnet next to eh cathode ray. He found out that they were almost all negative, or beta particles. He also determined the charge to mass ratio and came up with the idea that an atom was like plum pudding; mostly pudding(positive 'goo') but every once in a

  • Werner Heisenberg

    he created matrix mechanics, the first version of quantum mechanics in 1925
    he calculated the behavior of electrons, and subatomic particles that also make up an atom