History Of The Periodic Table Of Elements Essay

1141 Words Oct 24th, 2014 5 Pages
History of the periodic table of elements The periodic table of elements is an organized table of all chemical elements identified and recognized. Most forms of the table commonly include information such as each element’s atomic number, chemical properties, and electron configuration. Prior to the periodic table, the elements were arranged in groups of three called triads. These triads were created by Johann Dobereiner, a German chemist, in 1829. Dobereiner arranged these elements in groups of three based on patterns he found in the atomic masses of elements. An English chemist named John Newlands also tried to organize the elements. He created the Law of Octaves but it did not prove to be accurate for any elements heavier than calcium (cK-12 1-2). The creation of the periodic table is credited to Dmitri Mendeleev, a Russian chemist. Mendeleev arranged the periodic table in correspondence with the atomic mass of each element. As shown in figure 1, he arranged the families horizontally and the periods vertically. He found that when he arranged the elements in horizontal rows, leaving blanks for elements he had not discovered, a certain pattern regarding the chemical properties appeared regularly or periodically in vertical columns (AIP 1). With this new knowledge, Mendeleev was able to accurately predict the properties of 2 undiscovered elements, which are now known as gallium and germanium. Today’s periodic table is simply an advanced version of Mendeleev’s ideas.…

Related Documents