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Democritus (460 BC - 370 BC)
Democritus suggested that everything is composed of atoms and that between every atom there is empty space.
He also said that atoms are indestructible, that they are always moving, that there is an infinite number of atoms and that atoms are not all the same shape.
Source: http://en.wikipedia.org/wiki/Democritus -
Isaac Newton (1642 - 1727)
Isaac Newton was famous for creating his planetary system model, which the model of an atom is based off of.
He also suggested that atoms were held together by attractions that we call forces.
Source: http://en.wikipedia.org/wiki/Isaac_newton -
John Dalton (1766 - 1884)
Dalton created the first atomic table, which included only 6 elements; hydrogen, oxygen, nitrogen, carbon, sulphur and phosphurus.
His table also included some of the first atomic weights.
Source: http://en.wikipedia.org/wiki/John_Dalton -
Michael Faraday (1791 - 1867)
Michael Faraday was famous for studying the effect of splitting a molecule with electricity, with his finiding from this experiment he developed the laws of electrolysis.
He also verified that atoms are held together by electrical forces.
Source: http://www.xtimeline.com/evt/view.aspx?id=173855 -
Julius Plucker (1801 - 1868)
Julius Plucker was most well known for creating the Cathode Ray Tube. He had no actual connection to the atomic model btu his creation was very usefull in finding all that we know today.
Source: http://en.wikipedia.org/wiki/Julius_Pl%C3%BCcker -
George Johnstone Stoney (1826 - 1911)
George Johnstone Stoney discovered the electron and with this discovery proved that atoms have a charge.
Source: http://en.wikipedia.org/wiki/George_Johnstone_Stoney -
Dmitri Mendeleev (1801 - 1868)
Dmitri Mendeleev was the creator of one of the most fundamental parts of science to date; the periodic table.
He did not actually discover anything new about the atom.
Source: http://en.wikipedia.org/wiki/Dmitri_Mendeleev
http://answers.yahoo.com/question/index?qid=20090119075634AAHnjNo -
J.J. Thomson (1856 - 1940)
Thomson suggested that an atom was made up of a sphere of positive charge with negatively charged electrons within it.
He also said that the positive and negative charges in a an atom are equal therefore meaning that atoms are neutral.
Source: http://www.tutorvista.com/science/thomsons-atomic-theory -
Ernest Rutherford (1871 - 1937)
Rutherford suggested that there was a central positive nucleus and that it is surrounded by negative electrons.
He also discovered that most of the atom is contained in the nucleus.
Source: http://www.rsc.org/chemsoc/timeline/pages/1911.html -
Niels Bohr (1885 - 1962)
Bohr suggested that electrons travel in stationary orbit and that there is an emission of light when an electron moves into the lower energy orbit.
Source: http://en.wikipedia.org/wiki/Niels_Bohr -
Erwin Schrodinger (1887 - 1961)
He said that electrons are arranged in orbitals, which are distributed thoughout electron clouds.
He also said that Electron are not ina configuration of shells or energy levels.
Source: http://en.wikipedia.org/wiki/Erwin_Schrödinger -
Frederick Soddy (1877 - 1956)
He discovered that the strange behaviour of radioactive elemetns occurred because they were decaying into other elements, he found that this decay created radiation.
He proved that atomic radiation can occur when radioactive elements are present.
Source: http://en.wikipedia.org/wiki/Frederick_Soddy -
Louis de Broglie (1892 - 1987)
Louis de Brogie discovered that electrons act similar to light in that they can act like waves or particles.
He also discovered that electron waves set up a standing wave of a certain energy, frequency and wavelength.
Source: http://the-history-of-the-atom.wikispaces.com/Louis+de+Broglie -
James Chadwick (1891 - 1974)
James Chadwick is most well known for discovering a new particle in the atomic nucleus known as an electron. He also stated that the number of protons determines the atomic number.
Source: http://jameschadwickatomictheory.weebly.com/ -
Enrico Fermi (1901 - 1954)
Enrico Fermi developed the beta decay theory. He discovered that when a neutron decays to a proton it emitts a electron and a particle called a neutrino.
Source: http://inventors.about.com/od/fstartinventors/a/Enrico_Fermi.htm
