Repin's master of science, Mendeleev

This is a portrait of the Russian portrait master Repin in 1885 for the world-famous Russian scientist Mendeleev, who is dressed in a professor's uniform at the University of Edinburgh.

Dmitry Ivanovich Mendeleev (Дми́трий Ива́нович Менделе́ев, February 7, 1834 – February 2, 1907), Russian scientists discovered the periodic law of elements (the British chemist Neulands had discovered before him that Mendeleev had summarized and improved the periodic law of elements in use). Based on atomic weight, the world's first periodic table of elements was produced, and some elements that had not yet been discovered were foreseen. His famous book "Principles of Chemistry" is recognized by the international chemical community as a standard work, and has been reprinted eight times before and after, influencing generations of chemists. On February 2, 1907, the world-renowned Russian chemist died of a myocardial infarction.

The United Nations General Assembly declared 2019 the International Year of the Periodic Table of Chemical Elements, which commemorates the russian chemist Mendeleev's publication of the periodic table 150 years ago, a major achievement in the history of scientific development.

Biography

Mendeleev (Дмитрий Иванович Менделеев) was born on February 7, 1834 in Tobolsk, Siberia, and died in Petersburg on February 2, 1907.

"Mendeleev" at work

In 1848, he entered the State Chiao University of Petersburg, in 1850 he entered the Petersburg Teachers' College to study chemistry, in 1855 he qualified as a teacher, won the gold medal, and after graduation became a teacher of the Odessa Secondary School.

In 1856 he received an advanced degree in chemistry, and in 1857 he was inaugurated to a university position as an associate professor at the University of Petersburg. In 1859 he went to heidelberg university in Germany for further studies.

In 1860, he participated in the Congress of Internationalists in Karlsruhe.

In 1861, he returned to Petersburg to work as a scientific writer.

In 1863, he became a professor at the Faculty of Technology.

In 1864 Mendeleev became professor of chemistry at the Technical Academy, and in 1865 he received a doctorate in chemistry.

In 1866 he was appointed Professor of General Chemistry at the University of Petersburg, and in 1867 he was appointed Director of the Department of Chemistry.

In 1878, Mendeleev, together with Pavlov, founded the world-famous public research university, Tomsk State University.

From 1893, he was Director of the Bureau of Weights and Measures.

He was elected a Foreign Fellow of the Royal Society in 1890.

On February 2, 1907, the famous Russian chemist Mendeleev died at the age of 73. [2] In honor of this great scientist, in 1955, A. Gniorso, B.G. Harvey, G.R. Choppin, and others in the United States bombarded cadmium (253Es) with helium nuclei in accelerators, and the cadmium combined with helium nuclei to launch a neutron, and a new element was obtained, which was named Mendelevium (Md) after Mendeleyev.

Mendeleev's greatest contribution to the development of the discipline of chemistry was the discovery of the periodic law of the chemical elements. On the basis of the critical inheritance of the work of his predecessors, he revised, analyzed, and generalized a large number of experimental facts, and concluded the law that the properties of elements (and the elements and compounds formed by them) change periodically with the increase of atomic weight (now called relative atomic mass according to national standards), that is, the periodic law of elements. He compiled the first periodic table according to the periodic law of the elements, and included all 63 elements that had been discovered in the table, thus initially completing the task of systematizing the elements. He also left a space in the table, predicting the properties of unknown elements similar to boron, aluminum, and silicon (Mendeleev called it boron-like, aluminum-like, and silicon-like, i.e., scandium, gallium, and germanium later discovered), and pointed out that the values of the atomic weights of some elements measured at that time were incorrect. Nor did he mechanically arrange the atomic weights in the periodic table in exactly the order of the atomic weight values. Years later, his prophecies were confirmed. The success of Mendeleev's work caused a shock in the scientific community. In order to commemorate his merits, people called the periodic law and periodic table of the elements Mendeleev and the periodic table of the mendeleev elements.

Middle-aged "Mendeleev"

The road to the peak of science is a difficult and tortuous road. Mendeleev also suffered a lot on this road. When he became an associate professor of chemistry, he was responsible for teaching the course "Fundamentals of Chemistry". In theoretical chemistry, how many elements are in nature? What are the similarities and differences between elements and what are the internal connections? How should new elements be discovered? These problems were in the exploratory stage of the chemical community at that time. For nearly fifty years, chemists from all over the world have made tenacious efforts to open this secret door. Although some chemists such as De Bellena and Newlands objectively describe some of the connections between the elements at a certain depth and from different angles, they have not found the correct classification principles for the elements because they do not generalize all the elements as a whole. The young scholar Mendeleev also rushed into the field without fear and began a difficult exploration work.

Mendeleev's periodic table of elements in 1871

He studied day and night, exploring the chemical properties of the elements and their general atomic properties, and then wrote down each element and their atomic number on a small paper card. He attempts to capture the commonality of elements in all their complex properties. But his research, again and again, failed. But he did not give in, did not lose heart, and insisted on doing it.

In order to solve this problem once and for all, he walked out of the laboratory and began to go out to investigate and sort out and collect data. In 1859, he went to Heidelberg, Germany, for further scientific studies. During the two years, he concentrated on physical chemistry, which made his exploration of the intrinsic connections between elements more solid. In 1862, he made an expedition to the Baku oil field, conducted in-depth studies of liquids, and re-measured the atomic weight of some elements, giving him a deep understanding of the properties of the elements. In 1867, he took the opportunity of being invited to participate in the Russian Exhibition Hall of the World Industrial Exhibition held in France, and visited and inspected many chemical factories and laboratories in France, Germany and Belgium, which opened his eyes and enriched his knowledge. These practical activities not only increased his ability to understand nature, but also laid the foundation for his discovery of the periodic law of the elements. Mendeleev returned to the laboratory and continued to study his paper cards. He arranged the elements of the reassigned atomic weight in order of the size of the atomic weight. He found that elements with similar properties were not similar in atomic weight; on the contrary, some elements with different properties had similar atomic weights. He grasped the interrelationship between the atomic weight and the properties of the elements and kept studying them. His brain was often dizzy due to excessive tension. However, his efforts were not in vain, and on February 19, 1869, he finally discovered the periodic law of the elements. His periodic law states that the properties of simple objects, as well as the form and properties of elemental compounds, are cyclically dependent on the size of the atomic weight of the elements. In the process of arranging the table of elements, Mendeleev boldly pointed out that some of the recognized atomic weights at that time were inaccurate. If the atomic weight of gold was recognized as 196.2 at that time, according to this in the element table, gold should be ranked first in osmium, iridium, and platinum, because their recognized atomic weights were 198.6, 196.7, and 196.7, respectively, while Mendeleev firmly believed that gold should be ranked after these three elements, and the atomic weight should be redetermined. The results of the retest were 190.9 osmium, 193.1 iridium, 195.2 platinum, and 197.2 gold. Practice confirmed Mendeleev's assertion and proved the correctness of the periodic law.

In Mendeleev's periodic table, there are still many spaces left, which should be filled by elements that have not yet been discovered. Mendeleev theoretically calculated the most important properties of these yet-to-be-discovered elements, concluding that they were somewhere between the properties of neighboring elements. For example, in the two spaces between zinc and arsenic, he predicted the properties of these two unknown elements, aluminum-like and silicon-like, respectively. Just four years after his prediction, the French chemist Bouablanc used spectroscopy to discover gallium from the sphalerite. Experiments have shown that the properties of gallium are very similar to aluminum, that is, the aluminum-like predicted by Mendeleev. The discovery of gallium is of great significance, which fully demonstrates that the periodic law of elements is an objective law of nature; it provides a law to follow for the study of elements in the future, the exploration of new elements, and the search for new materials and new materials. The law of elemental periodicity is like a heavy cannon, roaring in the sky above the world!

In 1878, Mendeleev and Pavlov founded the world-famous public research university, Tomsk University.

The regret of the Nobel Prize

The failure of Dmitri Mendeleyev to win the Nobel Prize should be the most shocking and regrettable event in the history of Nobel Prizes. The Russian scientist discovered the periodicity of chemical elements, produced the world's first periodic table of elements, and used it to foresee some elements that had not yet been discovered. According to the Nobel archives, the Nobel Prize Committee had intended to award the 1906 Chemistry Prize to the master, but one of the committee members eventually kicked Mendeleev out of the list. The great chemist died in 1907.

Mendeleev discovered the periodic law of the elements, which left an immortal glory in the world, and people gave him a high evaluation. Engels pointed out in his book Dialectics of Nature. "Mendeleev unconsciously applied Hegel's law of quantity into quality, and completed a scientific merit that could be on an equal footing with Leviri's effort to calculate the orbit of the yet-unknown planet Neptune." Due to the limitations of the times, Mendeleev's periodic law of elements is not complete. In 1894, the discovery of the noble gas argon was a test and complement to the periodic law. In 1913, the British physicist Moseley, after studying the relationship between the wavelengths of Röntgen rays of various elements and the atomic number, confirmed that the atomic number was equal in quantity to the positive charge carried by the nucleus, and then made it clear that the basis of the periodic law was not atomic weight but atomic number. The theory of atomic structure produced under the guidance of the periodic law not only gives a new explanation to the periodic law of the elements, but also further clarifies the nature of the periodic law, placing the natural law of the periodic law on a more rigorous and scientific basis. The periodic law of elements has been continuously improved and developed by later generations, and plays an increasingly important role in people's struggle to understand nature, transform nature, and conquer nature.