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500
Democritus
460-370 B.C.. Suggested that matter could not be infinitely divided. Coined the term atom.daild to find out what held atoms together. -
Aug 26, 600
Aristotle
384-322 B.C.. Disagreed with Democritus.completely denied the idea of the atom because of his personal beliefs -
John Dalton
English schoolteacher that who marks the beginning of modern atomic theory. Belived atoms are the smaller particle. -
J.J Thompson
Designed a series of CRT experiments at Cambridge. To determine the ratio of the partle charged to its mass. Concluded the mass of the particle was much smaller than that of the -
Robert Millikan
Designed oil drop appersrus to determine the charge of the electron. Concluded it had a negative charge of -1. -
James Chadwick
Demonstrated that the necleus had a neutral sub atomic particle, the neutron. Won noble prize in 1935. -
Ernest Rutherford
Studies how positively changed a-particle interacted with solid matter. He calculated that the atom was mostly just empty space.
