History of the Periodic Table: Difference between revisions

In 1869, 63 elements had been discovered. As the number of elements grew larger, scientists begin to see certain patterns in the elements. <ref>Western Oregon University. [https://www.wou.edu/las/physci/ch412/perhist.htm A BRIEF HISTORY OF THE DEVELOPMENT OF PERIODIC TABLE] ''wou''. Accessed May 21, 2017</ref> In 1829, Johann Dobereiner observed that there were groups of elements with properties that were similar. Chlorine, bromine, and iodine were some of the elements that he saw similarities in. These elements were gases, had a similar color, and other similar qualities. Dobereiner begin to construct triads with the elements, but these eventually fell through and did not all fit together. <ref name=BJU>Batdorf, Brad. [The Periodic Table, Chapter 5] ''

BJU Chemistry, Third Edition''. Published 2009.</ref> Then in 1864 John Newlands thought that the elements may be able to be arranged according to atomic weight. He tried to arrange them in order of increasing atomic weight. This idea would not work because it groups elements together that have different chemical properties. But, he did take steps in leading to the creation of the periodic table. Newlands was the first person to add atomic numbers to the elements, which are on the [[periodic table]] to this day. <ref>Purdue. [http://chemed.chem.purdue.edu/genchem/history/newlands.html John Newlands] ''Purdue edu''. Accessed May 21, 2017.</ref>