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Dmitri Mendeleev

2007 Schools Wikipedia Selection. Related subjects: Chemists

   Portrait of Dimitri Mendeleyev by Ilya Repin
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   Portrait of Dimitri Mendeleyev by Ilya Repin

   Dimitri Mendeleev (Russian: Дми́трий Ива́нович Менделе́ев, Dmitriy
   Ivanovich Mendeleyev listen ) ( 8 February 1834 [ O.S. 27 January] in
   Tobolsk – 2 February 1907 [ O.S. 20 January] in Saint Petersburg), was
   a Russian chemist. He is credited as being the primary creator of the
   first version of the periodic table of elements. Unlike other
   contributors to the table, Mendeleev predicted the properties of
   elements yet to be discovered.

Early life

   Dmitri Mendeleev was born in Tobolsk, Siberia, to Ivan Pavlovich
   Mendeleev and Maria Dimitrievna Mendeleeva (nee Kornilieva). Mendeleev
   was the 13th surviving child of 17 total, but the exact number differs
   among sources. As a child, he was fascinated by the glass which was
   created at the factory his mother owned, and for a time, the young
   Mendeleev worked there. At the age of 13, after the death of his father
   and the destruction of his mother's factory by fire, Mendeleev attended
   the Gymnasium in Tobolsk.

   In 1849, the now poor Mendeleev family relocated to St. Petersburg,
   where he entered the Main Pedagogical Institute in 1850. After he
   graduated, an illness that was diagnosed as tuberculosis caused him to
   move to the Crimean Peninsula on the northern coast of the Black Sea in
   1855. While there he became chief science master of the local
   gymnasium. He returned with fully restored health to St. Petersburg in
   1857.

   Between 1859 and 1861, he worked on the capillarity of liquids and the
   workings of the spectroscope in Heidelberg. In 1862, he married Feozva
   Nikitichna Leshcheva. Mendeleev became Professor of Chemistry at the
   Saint Petersburg Technological Institute and the University of St.
   Petersburg in 1863, achieved tenure in 1867, and by 1871 had
   transformed St. Petersburg into an internationally recognized centre
   for chemistry research. In 1865 he became Doctor of Science for his
   dissertation "On the Combinations of Water with Alcohol". In 1876, he
   became obsessed with Anna Ivanovna Popova and began courting her; in
   1881 he proposed to her and threatened suicide if she refused. His
   divorce from Leshcheva was finalized one month after he had married
   Popova in early 1882. Even after the divorce, Mendeleev was technically
   a bigamist; the Russian Orthodox Church required at least 7 years
   before lawful re-marriage. His divorce and the surrounding controversy
   contributed to his failure to be admitted to the Russian Academy of
   Sciences (despite his international fame by that time). His daughter
   from his second marriage, Lyubov, became the wife of the famous Russian
   poet Alexander Blok. His other children were son Volodya and daughter
   Olga, from his first marriage to Feozva, and son Ivan and a pair of
   twins from Anna.

   Though Mendeleev was widely honored by scientific organizations all
   over Europe, including the Copley Medal from the Royal Society of
   London he resigned from St. Petersburg University on August 17, 1890.

   In 1893, he was appointed Director of the Bureau of Weights and
   Measures. It was in this role that he was directed to formulate new
   state standards for the production of vodka. His fascination with
   molecular weights led him to conclude that to be in perfect molecular
   balance, vodka should be produced in the ratio of one molecule of ethyl
   alcohol diluted with two molecules of water, giving a dilution by
   volume of approximately 38% alcohol to 62% water. As a result of his
   work, in 1894 new standards for vodka were introduced into Russian law
   and all vodka had to be produced at 40% alcohol by volume.

   Mendeleev also investigated the composition of oil fields, and helped
   to found the first oil refinery in Russia.

   Mendeleev died in 1907 in St. Petersburg, Russia from influenza. The
   Mendeleev crater on the Moon, as well as element number 101, the
   radioactive mendelevium, are named after him.

Periodic table

   One form of Mendeleev's periodic table, from the 1st English edition of
   his textbook (1891, based on the Russian 5th edition)
   Enlarge
   One form of Mendeleev's periodic table, from the 1st English edition of
   his textbook (1891, based on the Russian 5th edition)

   After becoming a teacher, he wrote the definitive two-volume textbook
   at that time: Principles of Chemistry (1868-1870). As he attempted to
   classify the elements according to their chemical properties, he
   noticed patterns that led him to postulate his Periodic Table.

   Unknown to Mendeleev, several other scientists had also been working on
   their own tables of elements. One was John Newlands, who published his
   Law of Octaves in 1864. However, the lack of spaces for undiscovered
   elements and the placing of two elements in one box were criticised and
   his ideas were not accepted. Another was Lothar Meyer, who published a
   work in 1864, describing 28 elements. Like Newlands, Meyer did not seem
   to have the idea of using a table to predict new elements. In contrast
   to Newlands' methodical approach to creating a table, Mendeleev's was
   almost accidental and emerged gradually.

   As a better understanding of atomic weights was developed and better
   data became available, Mendeleev made for himself the following table:
   Cl 35.5 K 39   Ca 40
   Br 80   Rb 85  Sr 88
   I 127   Cs 133 Ba 137

   By adding additional elements following this pattern, he developed his
   version of the 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 weight and valence. This presentation stated that
    1. The elements, if arranged according to their atomic mass, exhibit
       an apparent periodicity of properties.
    2. Elements which are similar as regards to their chemical properties
       have atomic weights which are either of nearly the same value
       (e.g., Pt, Ir, Os) or which increase regularly (e.g., K, Rb, Cs).
    3. The arrangement of the elements in groups of elements in the order
       of their atomic weights, corresponds to their so-called valencies,
       as well as, to some extent, to their distinctive chemical
       properties; as is apparent among other series in that of Li, Be, B,
       C, N, O, and F.
    4. The elements which are the most widely diffused have small atomic
       weights.
    5. The magnitude of the atomic weight determines the character of the
       element, just as the magnitude of the molecule determines the
       character of a compound body.
    6. We must expect the discovery of many yet unknown elements–for
       example, two elements, analogous to aluminium and silicon, whose
       atomic weights would be between 65 and 75.
    7. The atomic weight of an element may sometimes be amended by a
       knowledge of those of its contiguous elements. Thus the atomic
       weight of tellurium must lie between 123 and 126, and cannot be
       128. Here he was wrong as the atomic mass of tellurium (127.6)
       remains higher than that of iodine (126.9).
    8. Certain characteristic properties of elements can be foretold from
       their atomic weights.

   Only a few months after Mendeleev published his periodic table of all
   known elements (and predicted several new elements to complete the
   table), Meyer published a virtually identical table. Some people
   consider Meyer and Mendeleev the co-creators of the periodic table,
   although most agree that Mendeleev's accurate prediction of the
   qualities of what he called eka-silicon (germanium), eka-aluminium
   (gallium), and eka-boron (scandium) qualifies him for deserving the
   majority of the credit.

   As others before him had done, he questioned the accuracy of accepted
   atomic weights, pointing out that they did not correspond to those
   predicted by the Periodic Law.

Other achievements

   Mendeleev made other important contributions to Russian chemistry. The
   Russian chemist and science historian L.A. Tchugayev has characterized
   him as "a chemist of genius, first-class physicist, a fruitful
   researcher in the fields of hydrodynamics, meteorology, geology,
   certain branches of chemical technology (explosives, petroleum, and
   fuels, for example) and other disciplines adjacent to chemistry and
   physics, a thorough expert of chemical industry and industry in
   general, and an original thinker in the field of economy." Mendeleev
   was one of the founders, in 1869, of the Russian Chemical Society. He
   worked on the theory and practice of protectionist trade and on
   agriculture.

   In 1902, in an attempt at a chemical conception of the Aether, he put
   forward a hypothesis that there existed two inert chemical elements of
   lesser atomic weight than hydrogen. Of these two proposed elements, he
   thought the lighter to be an all-penetrating, all-pervasive gas, and
   the slightly heavier one to be a proposed element, coronium.

   Mendeleev devoted much study, and made important contributions to, the
   determination of the nature of such indefinite compounds as solutions.

   In another department of physical chemistry, he investigated the
   expansion of liquids with heat, and devised a formula similar to
   Gay-Lussac's law of the uniformity of the expansion of gases, while as
   far back as 1861 he anticipated Thomas Andrews' conception of the
   critical temperature of gases by defining the absolute boiling-point of
   a substance as the temperature at which cohesion and heat of
   vaporization become equal to zero and the liquid changes to vapor,
   irrespective of the pressure and volume.

   Mendeleev is given credit for the introduction of the metric system to
   the Russian Empire.

   He invented pyrocollodion, a kind of smokeless powder based on
   nitrocellulose. This work had been commissioned by the Russian Navy,
   which however did not adopt its use. In 1892 Mendeleev organized its
   manufacture.

   Mendeleev studied petroleum origin and concluded that hydrocarbons are
   abiogenic and form deep within the earth. He wrote: "The capital fact
   to note is that petroleum was born in the depths of the earth, and it
   is only there that we must seek its origin." (Dmitri Mendeleev, 1877)
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