I.    Ancient Greeks
        A.    Aristotle
               ~ believed there were 4 elements:

        B.    Democritus
               ~ believed in the "particle theory":

                ~ named the small particles "atoms" which means

II.    Dalton (1808)
        A.    Father of Atomic Theory
    Matter is composed of atoms
        C.    Points to his theory
               ~ atoms of an element

                ~ in chemical reactions,

III.    Thomson (1897)
        A.    discovered the
        B.    used a

IV.    Millikan (1909)
        A.   discovered electrons have
        B.   his experiment called

V.    Rutherford (1911)
        A.    discovered
        B.    his experiment called

VI.    Bohr (1913)
        A.    electrons
        B.    his model called
        C.    energy must be

VII.    Chadwick (1932)
        A.    discovered

VIII.    Progression of the atomic model

Democritus/Dalton  -->  Thomson  -->&nbssp; Rutherford  -->  Bohr  -->  Quantumm Mechanical




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