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Dmitry Mendeleev

Dmitry Mendeleev (Picture 1)

Dmitry Mendeleev (February 7, 1834 – February 2, 1907), Russian scientists, discovered the periodicity of chemical elements (but the first to discover the periodic law of the elements is Newlands, Mendeleev was later summed up and improved to obtain the periodic law of the elements used now. According to the atomic quantity, the world's first periodic table of elements was produced, and some undiscovered elements were foreseen. On February 2, 1907, the world-renowned Russian chemist died of a myocardial infarction, only five days from his 73rd birthday. His masterpiece, the "chemical principle" born with the law of the elemental cycle, was recognized as a standard work by the international chemical community in the late nineteenth and early twentieth centuries. There were eight editions before and after, affecting chemists from generation to generation.

Mendeleev was born on February 7, 1834 in Tobolsk, Siberia, and died in Peterborough on February 2, 1907. In 1848, he entered the National Transportation University of Petersburg. In 1850, he entered the Peterborough Teachers College to study chemistry. In 1855, he obtained teacher qualifications and received a gold medal. After graduation, he was a teacher at Odessa Middle School. He received a high degree in chemistry from 1856 and first held a university position in 1857. He is an associate professor at the University of Petersburg. In 1859 he went to the University of Heidelberg, Germany for further study. In 1860 he participated in the International Congress of Chemists in Karlsruhe. In 1861, he returned to Petersburg to work on scientific writing. In 1863, he was a professor at the Institute of Technology. In 1864, Mendeleev was a professor of chemistry at the Technical College. In 1865, he received a Ph.D. in chemistry. In 1866, he was a professor of general chemistry at the University of Petersburg, and in 1867 he was the director of the Chemistry Department. Since 1893, he has served as Director of the Bureau of Weights and Measures. In 1890 he was elected a foreign member of the Royal Society.

Mendeleev's greatest contribution to the development of chemistry is the discovery of the periodic law of chemical elements. On the basis of critically inheriting the work of his predecessors, he revised, analyzed and summarized a large number of experimental facts, summed up the rule that the nature of the element (and the simple substances and compounds formed by it) varies with the atomic weight (currently The national standard is called the relative atomic mass) and it changes periodically, which is the periodic law of the element. He compiled the first periodic table of elements according to the elemental cycle law, and included all the 63 elements that have been found in the table, thus initially completing the task of systematizing the elements.

Due to the limitations of the times, Mendeleev's elemental cycle law is not complete. In 1894, the discovery of rare gas argon was a test and supplement to the periodic law. In 1913, the British physicist Moseley studied the relationship between the wavelength of the X-ray and the atomic number of various elements, and confirmed that the atomic number is equal in number to the positive charge of the nucleus, and thus the basis of the periodic law is not the atomic weight. Is the atomic number. The atomic structure theory produced under the guidance of the periodic law not only gives a new explanation to the periodic law of the element, but further clarifies the nature of the periodic law, and puts the natural law of the periodic law on a more rigorous and scientific basis. Through the continuous improvement and development of the posterity, the elemental cycle law plays an increasingly important role in the struggle of people to understand nature, transform nature and conquer nature.

The failure of Dmitry Mendeleev to win the Nobel Prize should be the most shocking and regrettable thing 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 foreseen some undiscovered elements. According to the Nobel Archives, the Nobel Prize Committee had intended to award the 1906 Chemistry Prize to the Master, but one of the committees eventually kicked Mendeleev out of the list. On February 2, 1907, the famous Russian chemist Mendeleev died at the age of 73. To commemorate this great scientist, in 1955, A.Gniorso, BGHarvey, GRChoppin, etc. in the United States bombarded cesium (253Es) with a nucleus in the accelerator, and combined with a nucleus to emit a neutron. And obtained a new element, named after Mendeleev (Mendelevium, Md).

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