HISTORY
        The Greeks - Democrites
            smallest particle
                can't be divided
                    no proof
                    just what they observed

    Dalton's Model
        agreed w/ Greeks
        added -
                every atom of the same element
                        same mass
                        look alike
                can't be created or destroyed

    Thomson's Model
           existence of smaller particles
                - electron
 
            reasoning - there must also be a proton

    Rutherford
        student of Thomson's
        atom - mostly empty space
            found the nucleus
               http://www.mhhe.com/physsci/chemistry/essentialchemistry/flash/ruther14.swf

    Bohr's Model
        Electrons move in specific orbits
            specific energy levels

    Cloud Model
        Electron movement
            energy level

THE STRUCTURE OF THE ATOM
 
 

PARTS OF THE ATOM
    http://www.hazelwood.k12.mo.us/~grichert/atom/Periodic%20Law%20of%20the%20Elements/sld002.htm

    Nucleus
        protons
            1 amu
 postively charged
            represented on the Periodic Table as the atomic number

        neutrons
            1 amu (slightly more)
            made up of protons, electrons and energy
            neutral charge
            determines the isotopes

    Electron cloud with energy levels
        electrons
            1/2000 of an amu
            negatively charged
            arranged on the different energy levels
                octet rule first level 2;  second level 8;  third level 8
            movement depends on which level the electron is on
            valence electrons (# of electrons on the last energy level)
            determines the ion  (getting more electrons or having less than the # of protons)