Zack Canova
Mr. Schwartz
Adv. Chemistry
9/23/2012
Dmitry Ivanovich Mendeleev Russian chemist Dmitry Mendeleev was born in Tobolsk, Siberia, on February eighth, 1834. He studied natural science at St. Petersburg and graduated in Chemistry. In 1860, he went to Heidelberg. While he was there he started his own laboratory. In 1861, he became professor of chemistry in the technological institute. In 1890, he resigned and in 1893, he was appointed director of the Bureau of Weights and Measures. He remained in this position until his death. One of the achievements he is most known for is the development of the periodic table. In 1863, there were 56 known elements. Other scientists had previously identified periodicity of elements. Most ideas where criticized and where left unrecognized, until Mendeleev’s idea. He attempted to classify the elements according to their chemical properties. He noticed many patterns that led him to his final periodic table. On March 6, 1869, Mendeleev made a formal presentation to the Russian Chemical Society, entitled The Dependence between the Properties of the Atomic Weights of the Elements, which described elements according to both atomic weight and valence electrons. His presentation stated that if the elements are arranged by atomic weight, then they exhibit an obvious pattern of properties. Also, elements that are similar in regards to their chemical properties have atomic weights that are nearly the same. The arrangement of the elements was in order of their atomic weight. The elements that are most widely spread have small atomic weights. The magnitude of the atomic weight determined the character of the element. Mendeleev published his periodic table using all the known elements. He also predicted several new elements. For his predictions he used prefixes like eka, dvi, and tri in their naming. He was not sure where to put the know lanthanides, but he predicted another row to the table which were the actinides. The Actinides where some of the heaviest in atomic mass. Most
