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first element discovered
Hennig Brand discovered the first element- phospherous
info from www.edu/las/physci/ch412/perhist.htm
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John Dalton
atoms of a given element are identical in size, mass, and other properties; atoms of different elements differ in sixe, mass, and other properties. atoms cannot be subdivided, created, or destroyed.
info from http://en.wikipedia.org/wiki/John_Dalton#Atomic_weights
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first periodic table
the first periodic table was created. it was a list of elements in a cylinder in terms of increasing atomic weight.
info from www.wou.edu/las/physci/ch412/perhist.htm
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John Newlands
John Newlands wrote a paper classifying the 56 elemants into 11 groups based on similar physical properties.
info from www.wou.edu/las/physci/ch412/perhist.htm
picture from http://www.rsc.org/Education/Teachers/Resources/periodictable/scientists/newlands.jpg -
63 elements
by 1869 63 elements had been discovered.
info from www.wou.edu/las/physci/ch412/perhist.htm -
Lord Rayleigh
Lord Rayleigh discovered the noble gases.
info from www.wou.edu/las/physci/ch412/perhist.htm -
J.J. Thompson
He was the first to suggest that the fundimental unit was over 1000 times smaller than an atom, suggesting the sub-atomic particles now known as elections.
info from www.wou.edu/las/physci/ch412/perhist.htm
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Earnest Rutherford
Earnest Rutherford demonstrated that the nuclear charge on a nucleus was proportional the atomic weight of the elements.
info from www.wou.edu/las/physci/ch412/perhist.htm
picture from http://www.daviddarling.info/images/Rutherford_atomic_model.jpg -
bohr model
It describes most of the accepted features of atomic theory without all of the high-level math of the modern version. Unlike earlier models, the Bohr Model explains the Rydberg formula for the spectral emission lines of atomic hydrogen.
info from http://chemistry.about.com/od/atomicstructure/a/bohr-model.htm
picture from http://csep10.phys.utk.edu/astr162/lect/light/bohrframe/bohr2.gif -
Seaborg
Seaborg won a noble peace prize for his work in chemistry and element 106 was named in his honor (Sg)
info from www.wou.edu/las/physci/ch412/perhist.htm
