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460
Democritus
Democritus Theory stated that atoms which were physically, not geometrically indivisual; that between atoms, there lies empty space; that atoms are indestructible; have always been, and always will be, in motion; that there are an infinite number of atoms, and kinds of atoms, which differ in shape, and size. Of the mass of atoms, Democritus said "The more any indivisible exceeds, the heavier it is." -
John Dalton
Dalton publiished a table of relative Atomic Weights. Six elements appear in this table, namely hydrogen, oxygen, nitrogen, carbon, sulfur, and phosphorus. he thus arrived at the idea that chemical combination takes place between particles of different weights, and it was this which differentiated his theory from the historic speculations of the historic speculations of the Greeks, such as Democritus and Lucretius. -
J. J. Thomson
Thomson, in 1897, was the first to suggest that the fundamental unit was over 1000 times smaller than an atom, suggesting the subatomic particle now known as the electron. He won the Nobel Prize in Physics in 1906. -
Ernest Rutherford
Rutherford conducted the Gold foil Experiment. He corrected his professer JJ Thomson. He discovered the Proton. He won the nobel Prize in Chemistry in 1908. -
Niels Bohr
Bohr proposed a theory for the hydrogen atom based on quantum theory that energy is transferred only in certain well defined quantities. Electrons should move around the nucleus but only in prescribed orbits. When jumping from one orbit to another with lower energy, a light quantum is emitte -
Max Planc
PlanckAt the end of the 1920s Bohr, Heisenberg and Pauli had worked out the Copenhagen interpretation of quantum mechanics, but it was rejected by Planck, and by Schrödinger, Laue, and Einstein as well. Planck expected that wave mechanics would soon render quantum theory—his own child—unnecessary. This was not to be the case, however. Further work only cemented quantum theory, even against his and Einstein's philosophical revulsions. -
James Chadwick
ChadwickHe discovered the Neutron. The neutron is a particle with no charge. This completed all theorys because now there were a postive particle, a negative particle, and a neutral particle. He won the Nobel Prize in Physics in 1935.
