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Robert Boyle
At age of 34 boyle published the skeptical chymist.An element is a substance that cant be seperated into simpler components by chemical methods. -
Democritus
"By convention bitter, by convention sweet, but in reality atoms and void" This was a quote from him that explained what he learned and discovered about the atom -
Antoine Lavoiser
Experimentation skills one of his favorite experiments turning hg 0 into hg+ 0. He began the conversation on what an atom was exactly. -
John Dalton
Preposed an "atomic theory" with sperical soliid atoms based upon measurable properties of mass. -
Dmitri Mendeleev
Arranged elements into 7 groups with similar properties he discovered that the properies of elements were periodic funcitons of their atomoic weights. -
Eugen Goldstein
He concluded in addition to the electrons or cathode rays, that travel from the negatively charged cathode toweard the positively charged anode, there is another ray that travels in the opposite diretion, from the anode toward the cathode. -
J.J Thomson
Studied canal rays and found they were associated with the proton Ht. used a clzt to experimentally determine the charge to mass ratio (e/m) of an electron. -
Max Planck
used the idea of discrete units of energy to explain hot glowing matter. -
Robert Millican
Measured the charge on an electron witht he apparatus. Millican was able to show that the charge on a drop was always an interal multiple of a small, but final value. -
Ernest Rutherford
He established the nucleas was very dense, very small and positively charged. he also asumed that the electrons were located outside nucleas. -
Henry Mosely
published the results of his measurments of the wave lengths of the xray spectral lines of a number of elements which showed that the ordering of wave lengths of the x ray emissions of the elements concided witht he ordering of the elements by atomic number. -
Neils bohr
won noblel prize for saying an atom was a small positively charged nucleas. and it orbated around electrons