Dmitri Ivanovich Mendeleev was born January 27 (or February 8, New Style Calendar) 1834, in Tobolsk, Siberia, Russian Empire, and died January 20 (February 2), 1907, in Saint Petersburg, Russia.
Mendeleev was the Russian chemist who developed the periodic classification of the elements. He discovered that when all known chemical elements are arranged in order of increasing atomic weight, the resulting table displays a recurring pattern, or periodicity, of properties within groups of elements.
In his 1871 version of the periodic table, he left gaps where he thought unknown elements would appear. He even predicted the likely properties of 3 of these elements. The subsequent confirmation of many of his predictions during his lifetime brought Mendeleev fame as the founder of the periodic law.
Who was Dmitri Mendeleev?
Mendeleev was born in the small Siberian town of Tobolsk, the last of 14 surviving children (or 13, depending on the source) of Ivan Pavlovich Mendeleev, a teacher at the local gymnasium, and Mariya Dmitriyevna Kornileva, Britannica shows.
Dmitri’s father became blind the year Dmitri was born and died in 1847. To support the family, his mother turned to operating a small glass factory owned by her family in a nearby town. The factory burned down in December 1848, and Dmitri’s mother took him to Saint Petersburg, where he enrolled at the Main Pedagogical Institute.
His mother died shortly thereafter, and Mendeleev graduated in 1855. He received his first teaching post in Simferopol in the Crimea. He stayed there for only two months, and after a short time at the Odesa high school, he decided to return to St. Petersburg to continue his studies.
He received a master’s degree in 1856 and began conducting research in organic chemistry. Funded by a government scholarship, he went to study abroad for two years at the University of Heidelberg.
Instead of working closely with the university’s prominent chemists, including Robert Bunsen, Emil Erlenmeyer, and August Kekulé, Mendeleev set up a laboratory in his own apartment.
In September 1860, he attended the International Chemical Congress in Karlsruhe, convened to discuss crucial issues such as atomic weights, chemical symbols, and chemical formulas. There he met and established contacts with many of the leading chemists in Europe.
In later years, Dmitri particularly remembered a paper circulated by the Italian chemist Stanislao Cannizzaro that clarified the notion of atomic weights.
In 1861, Mendeleev returned to St. Petersburg, where he obtained a professorship at the Institute of Technology in 1864. After his doctoral thesis in 1865, he was appointed professor of chemical technology at the University of St. Petersburg (now State University Saint Petersburg). He became professor of general chemistry in 1867 and continued to teach there until 1890.
The periodic table of elements created by Mendeleev
As he began to teach inorganic chemistry, Mendeleev could not find a textbook that met his needs. Since in 1861 he had already published a textbook on organic chemistry, which had been awarded the prestigious Demidov Prize, he set out to write another.
The result was “Osnovy khimii” (1868–1871; Principles of Chemistry), which became a classic, undergoing several reprints and translations. When Mendeleev began composing the chapter on the halogen elements (chlorine and its analogues) at the end of the first volume, he compared the properties of this group of elements with those of the alkali metal group such as sodium.
Within these two different groups of elements, he discovered similarities in the progression of atomic weights and wondered whether other groups of elements exhibited similar properties.
After studying the alkaline earths, Mendeleev determined that the order of atomic weights could be used not only to arrange the elements within each group, but also to arrange the groups themselves. Thus, in his attempt to understand the extensive knowledge that already existed about the chemical and physical properties of the chemical elements and their compounds, Mendeleev discovered the law of periodicity.
His newly formulated law was announced before the Russian Chemical Society in March 1869, along with the statement “elements arranged according to the value of their atomic weights exhibit a clear periodicity of properties”.
Mendeleev’s law allowed him to construct a systematic table of all 70 elements then known. He was so confident in the validity of the periodic law that he proposed changes to the generally accepted values for the atomic weight of several elements and predicted the locations in the table for the unknown elements, along with their properties.
At first, the periodic table did not arouse interest among chemists. However, with the discovery of the predicted elements, notably gallium in 1875, scandium in 1879, and germanium in 1886, it began to gain wide acceptance.
Gradually, the periodic law and the table became the framework for much of chemical theory. By the time of Mendeleev’s death in 1907, he enjoyed international recognition and had received honors and prizes from many countries.
What other activities did Mendeleev have?
Mendeleev pursued many other activities outside of academic research and teaching. He was one of the founders of the Russian Chemical Society (now Mendeleev’s Russian Chemical Society) in 1868, and published most of his subsequent work in that society’s scientific journal.
He was a prolific thinker and writer. His published works include 400 books and articles, and numerous unpublished manuscripts are still preserved today in the Dmitri Mendeleev Museum and Archives at Saint Petersburg State University. In addition, to earn money, he began writing articles on popular science and technology for magazines and encyclopedias as early as 1859.
His interest in spreading scientific and technological knowledge was such that he continued to write about popular science until the end of his career, participating in the “Brockhaus Enzyklopädie” project and launching a series of publications entitled “Biblioteka promyshlennykh znany” (“The Library of industrial knowledge”) in the 1890s.
A man passionate about science
Dmitri was also interested in the development of Russia’s agriculture and industrial resources, but he also wanted to know more about the oil industry.
Altogether, he may have devoted more time to the problems of the national economy than to chemistry.
Thus, Mendeleev was able to combine his lifelong interests in science and industry and achieve one of his main goals: the integration of Russia into the Western world.