Atomic Theory

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    Democritus was an Ancient Greek philosopher born in Abdera, Thrace, Greece. He had the 1st Atomic Theory. He was a philosopher who formulated an atomic theory for the cosmos. His exact contributions are difficult to disentangle from his mentor Leucippus. Their hypothesis on atoms is remarkably similar to modern science's understanding of atomic structure, and avoided many of the errors of their contemporaries. Many consider Democritus to be the "father of modern science".
  • Dalton

    John Dalton developed the 1st useful atomic theory. Dalton concluded that evaporated water exists in air as an independent gas. He wondered how water and air could occupy the same space at the same time, when obviously solid bodies can't. He performed experiments on mixtures of gases to determine what effect properties of the individual gases had on the properties of the mixture vs. a whole. He developed the hypothesis that the sizes of the particles making up different gases must be different.
  • Rutherford

    Ernest Rutherford, widely referred to as Lord Rutherford, was a chemist and a physicist who became known as the "father" of nuclear physics. He pioneered the orbital theory of the atom through his discovery of Rutherford scattering off the nucleus with his gold foil experiment. He was awarded the Nobel Prize in Chemistry in 1908.
  • Thomson

    In 1897 in Cambridge, J J Thomson experimented on cathode rays. In Britain, physicists had argued these rays were particles, but German physicists disagreed, thinking they were a type of electromagnetic radiation. Thomson showed that cathode rays were particles with a negative electric charge and much smaller than an atom. He also thought all atoms contained them. These particles were later named electrons.
  • Bohr

    Niels Henrik David Bohr was a Danish physicist who made contributions to understanding atomic structure and quantum mechanics, for which he received the Nobel Prize in Physics in 1922. He was also part of the team of physicists working on the Manhattan Project. Bohr married Margrethe Nørlund in 1912, and their some,Aage Niels Bohr, grew up to be an important physicist, who also received the Nobel prize, in 1975. Bohr is considered to be the one of the greatest physicists of the 20th Century.
  • Goldstein

    In 1927 he became head of the astrophysical section of the Potsdam Observatory. Goldstein's best-remembered scientific work is his studies of electrical discharges in gases at low pressures. He gave the name ‘cathode rays’ to the invisible emanations coming from the cathode of an evacuated discharge tube, showing rays could cast sharp shadows & demonstrated they were emitted perpendicular to the cathode surface. He later showed that they could be deflected by magnetic fields.
  • Chadwick

    Sir James Chadwick was an English Nobel laureate in physics awarded for his discovery of the neutron. In 1932, he discovered an unknown particle in the nucleus. This particle became known as the neutron because of its lack of electric charge. For this discovery he was awarded the Hughes Medal of the Royal Society in 1932 and the Nobel Prize for Physics in 1935.