Periodic Table

Even though Dmitri Mendeleev is known as “The Father of the Periodic Table”, there are many important scientists who contributed to the making of the periodic table. In the late 1770’s, Antoine Lavoisier wrote the first list of elements, containing 33 of them. He was able to distinguish between metals and nonmetals, but some we were proven to be compounds and mixtures. In 1828, Jons Jakob Berzelius developed a periodic table of atomic weights. The following year, Johann Dobereriner developed triads, groups of 3 elements with similar properties. These included: Lithium, Sodium, and Potassium; Calcium, Strontium, and Barium; and Chlorine, Bromine, and Iodine. In 1862, A.E. Beguyer de Chancourtis lined up the groups vertically and was the first to recognize that the properties of elements reappear every seven elements. In 1864, John Newlands classified 56 elements into 11 groups based on similar physical properties. He created the Law of Octaves. Five years later, Lothar Meyer made a periodic table of 56 elements based on properties such as molar volume and atomic weight. The same year, Dmitri Mendeleev established a Periodic Table based on atomic weights arranged periodically by means of the periodic law, leaving gaps for unknown elements. In 1894, William Ramsey discovered the noble gases.

Ernest Rutherford showed that the nuclear charge on a nucleus was proportional to the atomic weight of elements in 1911. Three years later in 1914, Henry Mosely determined the atomic numbers of each of the elements, stating that the properties of the elements vary directly with their atomic numbers. Finally, in 1940, Glenn Seaborg discovered all the elements from 94 to 102 and reconstructed the periodic table for the last major changed to the Modern Periodic Table

Sources

http://www.wou.edu/las/physci/ch412/perhist.htm