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John Dalton
John Dalton proposed that all matter is composed of very small things called atoms. -
JJ Thomson
Used a CRT to experimentally determine the charge to mass ratio of an electron -
Ernest Rutherford
Studied radiations emitted from uranium and thorium and named them alpha and beta. -
Robert A. Millikan
Oil drop experiment determined the charge and the mass of an electron. -
Ernest Rutherford
Using alpha particles as atomic bullets, probed the atoms in a piece of thin gold foil . He established that the nucleus was: very dense,very small and positively charged. He also assumed that the electrons were located outside the nucleus. -
Niels Bohr
Developed an explanation of atomic structure that underlies regularities of the periodic table of elements. His atomic model had atoms built up of successive orbital shells of electrons.
