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Democritus
Proposed that earliest views on the shapes and connectivity of atoms. (460 BC) -
John Dalton
proposed an atomic theory with spherical atomic atoms based upon maeasurable properties of mass -
jj thomson
studied canal rays and found they were associated with th proton H+ -
ERNEST RUTHERFORD
Studied radiations emitted from uranium and thorium and named them Alpha and Beta. -
Niel 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.