Mendeleev Catalog [Hide] Dmitri Ivanovich Mendeleev Dmitri Ivanovich Mendeleev Law of the Period of Elements Mendeleev’s Life Famous Quotes The Exploration of the Period of Elements
Dmitri Ivanovich Mendeleev [Edit this paragraph] Dmitri Ivanovich Mendeleev Mendeleev successfully predicted The atomic number and properties of radium, and the radium product radon (liquid radium) was developed. [Edit this paragraph] Dmitri Ivanovich Mendeleev Russian chemist Mendeleev (Russian: Дми?0?7трий Ива?0?7нович Менделе?0?7ев, English: Dmitri Ivanovich Mendeleev, February 7, 1834 ~ February 1907 2), born in Tobolsk, Siberia, Russia. He has loved labor, nature and study diligently since he was a child.
When Mendeleev was considering writing plans for his book "Principles of Chemistry" in 1860, he was deeply troubled by the lack of systematicity in inorganic chemistry. Therefore, he began to collect information on the properties and related data of every known element, and collected all the results that his predecessors could find in practice. Humanity's long-term practice and cognitive activities on elemental issues have provided him with rich materials. On the basis of studying the results of his predecessors, he discovered that some elements not only have unique properties, but also have unique properties. For example, the known halogen elements fluorine, chlorine, bromine, and iodine all have similar properties; the alkali metal elements lithium, sodium, and potassium are quickly oxidized when exposed to the air, so they can only be in the form of compounds. Exist in nature; some metals such as copper, silver, and gold can remain in the air for a long time without being corroded. Because of this, they are called precious metals.
So Mendeleev began to try to arrange these elements. He built each element onto a rectangular cardboard card. Write the element symbol, atomic weight, element properties and its compounds on each rectangular piece of cardboard. Then they were nailed to the laboratory wall in rows and rows. After a series of queues, he discovered the regularity of the chemical properties of elements.
Therefore, when some people regard Mendeleev's discovery of the periodic law of elements as very simple and easily say that he obtained this great discovery by playing poker, Mendeleev took it seriously. He replied that it took him about 20 years to finally publish the periodic law of elements in 1869, ever since he decided to engage in this exploratory work. He sorted the chemical elements out of the chaotic maze into categories. In addition, because he has great courage and confidence, is not afraid of criticism or ridicule from celebrities, has the courage to practice and promote his own views, he has finally been widely recognized. In order to commemorate his achievements, the 101st new element discovered by American chemist Seaberg in 1955 was named Mendelevium, which means "mendelevium". [Edit this paragraph] Periodic law of elements The periodic law of elements reveals a very important and interesting law: the properties of elements change periodically as the atomic weight increases, but they do not simply repeat. Based on this principle, Mendeleev not only corrected some incorrect atomic weights, but also predicted the existence of more than 15 unknown elements. As a result, three elements were discovered while Mendeleev was still alive. In 1875, French chemist Lecoq de Bois-Baudran discovered the first element to be filled, naming it gallium. All the properties of this element are the same as Mendeleev predicted, except that the proportion is inconsistent. Mendeleev wrote a letter to the Paris Academy of Sciences, pointing out that the specific gravity of gallium should be about 5.9, not 4.7. At that time, the gallium was still in the hands of Boisbodhran, and Mendeleev had not yet seen it. This incident greatly surprised Boisbodran, so he tried to purify it and remeasure the specific gravity of gallium. The results confirmed Mendeleev's prediction that the specific gravity was indeed 5.94. This result has greatly improved people's understanding of the periodic law of elements. It also shows that many scientific theories are called truth, not when scientists create these theories, but when this theory is continuously confirmed by practice. When Mendeleev predicted new elements through the periodic table of elements, some scientists said that he was arrogantly inventing elements that did not exist. Through practice, Mendeleev's theory has received more and more widespread attention.
Later, based on the periodic law theory, people arranged and classified the more than 100 elements that had been discovered, and listed today's periodic table of chemical elements, which was posted on the laboratory wall and arranged behind the dictionary. It is a lesson that every student must learn and master when learning chemistry.
Now, we know that in the vast universe where humans live, all matter is composed of more than 100 elements, including us humans.
But, what are chemical elements? Chemical elements are collective names for atoms of the same type. Therefore, people often say that atoms are the "basic bricks" that constitute the material world. In a certain sense, this is true. However, the periodic law of chemical elements shows that chemical elements do not exist in isolation and are unrelated to each other. These facts mean that element atoms must also have their own internal laws. Changes in the theory of material structure are already here.
Finally, at the end of the 19th century, new developments occurred in practice, and radioactive elements and electrons were discovered. This was an excellent opportunity to reveal the inside story of atoms. But Mendeleev was confused in the face of practice. On the one hand, he was afraid that these discoveries would "complicate things" and shake "the foundation of the entire world view"; on the other hand, he felt that this "will be a very interesting thing...the reasons for the periodic patterns may be revealed." But Mendeleev himself died in 1907 with this contradictory thought on the eve of revealing the nature of the periodic law.
Mendeleev did not see that it was precisely because of a series of great discoveries and practices at the end of the 19th century and the beginning of the 20th century that the essence of the periodic law of elements was revealed and the theory of Mendeleev's era was abandoned. The old idea that atoms are indivisible. While discarding its inaccurate parts, it fully affirms its reasonable connotation and historical status. The new theory of the periodic law of elements born on this basis is more truthful than Mendeleev's theory.
1 H hydrogen 1.0079 2 He helium 4.0026 3 Li lithium 6.941 4 Be beryllium 9.0122 5 B boron 10.811 6 C carbon 12.011 7 N nitrogen 14.007 8 O oxygen 15.999 9 F fluorine 18.998
10 Ne 20.17 11 Na 22.9898 12 Mg 24.305 13 Al 26.982 14 Si 28.085 15 P 30.974 16 S 32.06 17 Cl 35.453
18 Ar 39.94 19 K 39.098 20 Ca Calcium 40.08 21 Sc 44.956 22 Ti 47.9 23 V Vanadium 50.94 24 Cr 51.996 25 Mn 54.938
26 Fe 55.84 27 Co 58.9332 28 Ni 58.69 29 Cu 63.54 30 Zn 65.3 8 31 Ga Gallium 69.72 32 Ge 72.5 33 As 74.922
34 Se 78.9 35 Br 79.904 36 Kr 83.8 37 Rb 85.467 38 Sr 87.62 39 Y Yttrium 88.906 40 Zr 91.2 2 41 Nb Niobium 92.9064 < /p>
42 Mo 95.94 43 Tc Technetium (99) 44 Ru 161.0 45 Rh 102.906 46 Pd 106.42 47 Ag 107.868 48 Cd 112.41 49 In 114.82
50 Sn 118.6 51 Sb Antimony 121.7 52 Te Tellurium 127.6 53 I Iodine 126.905 54 40.1 59 Pr Praseodymium 140.9 60 Nd 144.2 61 Pm Promethium (147) 62 Sm 150.3 63 Eu 151.96
64 Gd 157.25 65 Tb 158.9 66 Dy 162.5 67 Ho 164.9 68 Er Erbium 167.2 69 TmThulium 168.9 70 Yb 173.04 71 Lu 174.967
72 Hf 178.4 73 Ta 180.947 74 W 183.8 75 Re 186.207 76 Os 190.2 77 Ir 192.2 78 Pt Platinum 195.08 79 Au Gold 196.967
80 Hg mercury 200.5 81 Tl thallium 204.3 82 Pb lead 207.2 83 Bi bismuth 208.98 84 Po polonium (209) 85 At (201) 86 Rn radon (222) 87 Fr francium (223)
< p>88 Ra radium 226.03 89-103Ac-Lr Actinium series: 89 Ac Actinium (227) 90 Th Thorium 232.0 91 Pa Actinium 231.0 92 U Uranium 238.0 93 Np Neptunium (237) 94 Pu Plutonium (239,244)103 Lr铓(260) 104 Rf酒铓(257) 105 Db酒钅Du(261) 106 Sg酒酓(262) 107 Bh钅波(263) 108 Hs钅黑(262) 109 Mt钅 Mai(265)
110 Ds钅达(266) 111 Rg钅钅(272) 112 Uub(285) 113 Uut(284) 114 Uuq(289) 115Uup(289) 116Uuh(292) 117 Uus (294)
118 Uuo(293) [Edit this paragraph] Mendeleev’s life On January 27, 1907, the wind was freezing in Petersburg, the capital of Russia, and the sun was dim. The mercury dropped to more than 20 degrees below zero, and lanterns covered with black gauze were lit everywhere on the streets, creating a sad atmosphere. The funeral procession of tens of thousands of people moved slowly on the street. At the front of the procession, there was neither a wreath nor a portrait, but a large wooden sign carried by a dozen young students, with many squares painted on it. Gerry writes element symbols such as "C", "O", "Fe", and "Zn".
It turns out that the deceased was the famous Russian chemist Mendeleev, and the table with many squares painted on the wooden sign is the periodic table of chemical elements - Mendeleev's main contribution to chemistry.
Mendeleev was born into a family of a middle school principal who had seventeen children. He was the fourteenth. Just a few months after he was born, his father suddenly lost his sight and then lost his position as principal. Unable to make ends meet with a meager pension, the family moved to a nearby village where his uncle ran a small glass factory. The scene of workers smelting and processing glass had a great influence on his future chemical research involving beakers and flasks. In the autumn of 1841, Mendeleev, who was less than seven years old, and his teenage brother were admitted to the city middle school together, causing a sensation in the local area. Misfortune always follows poor people. When Mendeleev was 13 years old, his father died, and when he was 14 years old, the factory was reduced to ashes by fire. His mother had to move again, marry off her adult daughters, and let her two sons work. In the spring of 1849, when Mendeleev graduated from high school, his mother sold her property and wanted her youngest son to go to college. With the help of a friend of his father, Mendeleev entered the physics department of the Petersburg Teachers College. After only one year, he became a top student. In addition to intense study, he also wrote scientific reviews and received a small amount of royalties. By this time he had lost any financial support: his uncle and mother had died. In 1854, he graduated from university and won the gold medal of the college. He became an associate professor at the age of 23 and a professor at the age of 31.
The book that brought him initial fame was "Organic Chemistry". To write this book, he did not leave his desk for almost two months. After reaching the age of seventy, he became ill due to overwork and became half-blind. I work from early morning to 5:30 pm every day, and continue working after lunch until late at night. He died at his desk, still holding a pen in his hand. The discovery of the periodic law of elements in 1869 made him famous, and many foreign academies of sciences appointed him as an honorary academician. Once, a reporter asked him how he came up with the periodic law. Mendeleev laughed: "I have been thinking about this problem for 20 years, but you think I am sitting still. Five kopecks per line." , 5 kopecks arranged in a row, suddenly succeeded?"
Indeed, we should always remember Mendeleev's motto: "What is a genius? If you work hard for a lifetime, you will become a genius!" Edit this paragraph] Famous Quotes Life is about seeking new knowledge.
The seeds of science grow for the benefit of the people.
A theory that has not been tested in practice, no matter how beautiful it is, will lose its weight and will not be recognized by others; practice that is not based on a weighty theory will definitely fail.
Science can not only "give knowledge to the young and happiness to the elderly", but also make people accustomed to labor and the pursuit of truth, create real spiritual wealth and material wealth for the people, and create something that cannot be obtained without it.
For one person to discover the fruitful truth, it takes millions of people ruining their lives in failed explorations and tragic mistakes.
Genius is like this. If you work hard all your life, you will become a genius!
The seeds of science grow for the benefit of the people.
Without double diligence, there is neither talent nor genius. [Edit this paragraph] The road to explore the elemental cycle The road to climb 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 "Basics of Chemistry" course. In theoretical chemistry, it should be pointed out how many elements there are in nature? What are the similarities, differences, and internal connections between elements? How to discover new elements? These issues were at the exploratory stage in the chemical community at that time. In the past fifty years, chemists from various countries have made tenacious efforts to open the door to this secret. Although some chemists such as Debelena and Newlands objectively described certain connections between elements at a certain depth and from different angles, they did not find the correct classification principles for elements because they did not summarize all elements as a whole. . The young scholar Mendeleev also rushed into this field without fear and began the difficult exploration work.
He studied day and night, exploring the chemical properties of the elements and their general atomic properties, and then wrote down each element on a small paper card. He attempted to capture the uniqueness of elements in all their complex characteristics. His research failed again and again. But he didn't give in, didn't lose heart, and kept going.
In order to completely solve this problem, he walked out of the laboratory again and began to go out to inspect and organize and collect data. In 1859, he went to Heidelberg, Germany for further scientific studies. In two years, he concentrated on studying physical chemistry, which gave him a more solid foundation for exploring the inner connections between elements. In 1862, he conducted an inspection of the Baku oil fields, conducted in-depth research on liquids, and remeasured the atomic weights of some elements, which gave him a deep understanding of the characteristics of elements. In 1867, he took the opportunity of being invited to work at the Russian Exhibition Hall of the World Industrial Exhibition held in France. He visited and inspected many chemical plants 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 a solid foundation for his discovery of the periodic law of elements.
Mendeleev returned to the laboratory and continued to study his paper cards.
He arranged the elements with redetermined atomic weights in order of atomic weight. He discovered that elements with similar properties do not have similar atomic weights; on the contrary, some elements with different properties have similar atomic weights. He firmly grasped the relationship between the atomic weights and properties of elements and kept studying them. His brain was often dizzy due to excessive stress. However, his hard work was not in vain. On February 19, 1869, he finally discovered the periodic law of elements. His periodic law shows that the properties of simple objects, as well as the forms and properties of elemental compounds, are periodically dependent on the atomic weight of the element. In the process of arranging the table of elements, Mendeleev boldly pointed out that some of the generally accepted atomic weights at that time were inaccurate. For example, the atomic weight of gold at that time was recognized as 169.2. According to this, gold should be ranked in front of osmium and platinum in the table of elements, because their recognized atomic weights were 198.6 and 196.7 respectively. Mendeleev firmly believed that gold should be ranked After all three elements, the atomic weights should be redetermined. The results of everyone's retest showed that osmium was 190.9, platinum was 195.2, and gold was 197.2. Practice has confirmed Mendeleev's assertion and the correctness of the periodic law.
In the periodic table compiled by Mendeleev, there are still many blank spaces, 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 intermediate between those of neighboring elements. For example, in the two spaces between zinc and arsenic, he predicted that the properties of these two unknown elements would be aluminum-like and silicon-like respectively. Just four years after his prediction, French chemist Bouabran discovered gallium from Menzinc ore using spectroscopic analysis. Experiments have shown that the properties of gallium are very similar to aluminum, which is the aluminum-like properties predicted by Mendeleev. The discovery of gallium is of great significance. It fully demonstrates that the periodic law of elements is an objective law of nature; it provides a law that can be followed for future research on elements, exploration of new elements, and search for new substances and new materials.
The periodic law of elements roared over the world like a heavy cannon, and Mendeleev became famous all over the world!