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The 60 elements
60 elements known to humans were discovered by 1860 -
A list of the known elements
A list of all the known elements were published in 1862 by Alexandre Beguyer de Chancourtois -
The law of octaves
In 1863 John Newlands arranged the 62 known elemnts in order of increasing atmoic mass. -
mendeleeve
Mendeleeve ordered the elemnts to atomic weight. this was the first concept of the periodic table. -
Mendeleeve's revision of the periodic table
in 1871 mendeleeve revised his first periodic table. His new table exibhited to triads, verticle, horizontal and diagonal relatioonships in the elements -
Nobel gases
rayleigh reported a newly discorvered gas called argon. at the time of its discovery it did not fit into the element groups on that current periodic table -
Build of the periodic table
by the 20th century the periodic table was taking shape. Weights masses and discoveries of new elements led to more information about elements -
Moseley's Periodic Law
Mosely re-arranged Mendeleeves version of the periodic table by measuring the elements increasing atomic numbers not atomic mass -
Rutherfords Lnadmark
In 1911 Rutherfords Landmark experiment led him to the discovery of 'the poton' -
Glenn Seaborg
In 1950 glenn seaborg added transuranium elements to the periodic table