The Theory of The Atom

By Jamadroid
  • 400 BCE

    Democritus 460-370BC

    Democritus 460-370BC
    He was a Greek philosopher who first introduced the idea of atoms. He called it the atomus, which is Greek for "not cuttable".

  • Dalton 1775-1844

    Dalton 1775-1844
    His theory proposed that all the matter was made out of indivisible atoms. All of the atoms of one element were identical, and different elements had different atoms of size and weight. He also developed the system of symbols for the elements.

  • Thomson 1856-1940

    Thomson 1856-1940
    He was a physicist who first discovered the electron in 1897. He proposed the plum pudding model before the discovery of the nucleus. His model is made of the pudding (protons), and the raisins being electrons.

  • Rutherford 1871-1937

    Rutherford 1871-1937
    He was known as the father of nuclear physics, and held his famous gold foil experiment, by shooting alpha particles, which led to the discovery of the nucleus. He proposed the idea that all the positive charge is inside the nucleus.

  • Einstein 1879-1955

    Einstein 1879-1955
    He was a theoretical physicist and is best known for his theory of relativity. In 1905, he published an analysis of how to predict the size of atoms and molecules. This test was important to knowing that atoms were real.

  • Millikan 1868-1953

    Millikan 1868-1953
    He held the oil drop experiment which helped measure an electron's charge. He also found the specific size of the electron charge with the help of J.J. Thomson's experiment.

  • Bohr 1885-1962

    Bohr 1885-1962
    Bohr invented the Bohr atomic model with electrons orbiting the nucleus with special orbits. He supported the quantum theory which is based on his theory.

  • Schrodinger 1887-1961

    Schrodinger 1887-1961
    He is best known for the equation he made about quantum mechanics. He showed that waves could be used to describe electrons.

  • Heisenberg 1901-1976

    Heisenberg 1901-1976
    He included matrix mechanics into the atomic theory, and including the asserting of the uncertainty principle.

  • de Broglie 1892-1987

    de Broglie 1892-1987
    He was a French mathematician who is known for his discovery of particle-wave properties of an electron.

  • Chadwick 1891-1974

    Chadwick 1891-1974
    He was an English physicist and is famous for his discovery of the neutron. His discovery was crucial for the discovery of the fission of uranium.