Scientific History Miracle: The contribution of intuition beyond understanding

The following article comes from WeChat public account: Hui Pu, author John D. Barrow

Faced with more than sixty elements known, all chemists want to organize a system, but only one person has succeeded: he made a table with many blank white, as if a number of uniqueness.

And he never claims to understand the structure and periodic meaning of the table.

This article is authorized by the "Gallery of Science" (Renmin Post and Telecommunications Press), which is added by the editor.

Written article 丨 John D.barrow

Translation 丨 Tang Jing, Li Pan

When people are studying chemistry, they will use the element cycle table. There is no doubt that if the life of humans and the earth is contacted one day, the common points of the two smart civilizations will definitely include an orderly and well -known element table.

——John Emsley [1]

Under the guidance of Aristotle, ancient Greek philosophers believe that the material that exists in various forms and forms the world around us can be summarized by four basic substances, namely soil, fire, gas, and water. Before the 17th century, this rustic concept was respected as the facts, until the chemistry derived from alchemy was discovered by the existence of other elements. "Earth" is not a single material, but "qi" is not only composed of a gas. In the 18th century, the elemental spectrum has gone through dramatic growth. At that time, many new metals were discovered, such as cobalt, nickel, manganese, tungsten, chromium, magnesium, uranium, and new gases, such as hydrogen, nitrogen, oxygen, and chlorine. These gases were separated for the first time.

The concept of "elements" in chemistry was first proposed by Robert Bolitan: The substance that cannot continue to decompose with a physical process is elements. Since then, French chemist Antoine-Laurent de Lavoisier [2] officially named element in 1789 [3]. Lavaria selected 33 substances to define them for elements and divide them into four groups: metal, non -metal, soil and gas. Later, people found that some of these elements were actually compounds, other elements, such as heat and light, or even chemicals. The following is the element table of Lawarz. Only the elements marked as red are still considered chemical elements today.

Qi: heat, light, hydrogen, nitrogen, oxygen.

Earth: alumina, heavy spar, lime, magnesium oxide, silica.

Metal: Cycles, arsenic, coriander, cobalt, copper, gold, iron, lead, manganese, mercury, molybdenum, nickel, platinum, silver, tin, tungsten, zinc.

Non -metal: sulfur, phosphorus, carbon, chloride, fluoride, borate.

The "soil" group here is actually oxides, such as lime is calcium oxide, and silica is silicon. However, with the conditions at that time, Lavis cannot refine the oxygen atoms from the compounds, and independently recognize related elements of related elements. Essence Other false elements are in the "non -metal" group. Similarly, Lavis cannot separate these elements into single elements such as chlorine, fluorine and boron with the technology at that time. During the French Revolution, Lavais became the enemy of Jean -Paul Mara, and eventually was sent to the broken platform during the "terrorist rule" during the "terrorist rule" in 1794. The judge announced: "The Republic does not need a genius." But just after 18 months, the revolutionary government changed his mouth and said that Lavis was actually wronged.

After that, a scientific teacher from Manchester, England took a step further based on this study. In 1805, John Dalton submitted a dissertation to Manchester Literature and Philosophy Society to explain the various methods of combining elements and how the basic ingredients formed different weights. At that time, most chemists thought that atoms were too small and could not be studied. But Dalton was more adventurous. He proposed a table containing 20 elements and its weight, and marked the symbols that can express them. The substance is expressed by the drawings, and also shows the pattern of its basic composition elements. From this element table, more compounds can be derived: compound 21 is water, described as HO; compound 22 is ammonia, described as NH. These manifestations are the buds of chemical equations that are well known today.

However, Dalton's symbol is too complicated and cannot be used. The chemical symbols we use today are from Swiss chemist Jezs Berzelius [4], and he is also a admirationer of Dalton [5]. Beliculus uses element name (sometimes Latin, sometimes even Arabic, such as potassium, such as potassium) to simply mark the element, or use two letters in the case of vulnerable to ambiguity. For example, C represents carbon carbon carbon (Carbon), CO represents cobalt. Tie these symbols together, you can represent the compound, such as H2O. After 1835, this expression was used in large scale, and was eventually used in the equations that indicated chemical reactions, such as [6]:

Cuso4+ 2HCl → H2SO4+ CUCL2

Dalton was shocked by this new complexity produced by chemical language. After watching this new plan, he said: "A young chemical student may have to learn Hebrew." The new elements are constantly discovered, and Humphry Davy (Humphry Davy) uses an electrolytic method. The "soil element" initially proposed by tin was decomposed into real elements. There were more than 60 elements in 1863. Is there a limit of the element "Big Bang"? The 20 elements divided by John Dalton in 1805 and their weight

At that time, this was indeed an attractive problem. If there is a limit, how many elements are? What factor can really determine this limit?

In the 19th century, many people bravely tried to classify it from the perspective of element weight and attributes. At that time, all the best chemists [7] would establish a similar system [8]. However, they were defeated by a Russian chemistry professor from Siberia without exception.

Dmitri Ivanovich Mendeleev was born in 1822 in the home of a local primary school principal in Toppoosk in Siberia in 1822. He has 13 brothers and sisters. Menjiev's mother firmly believes that the son has special talents and should receive all possible high -quality education, so she sent her son to St. Petersburg to school. She is right. During college, Menjiev's academic performance has always been among the best. After that, he went to work in France and then went to Heidelberg, Germany to serve as the assistant of Robert Bunsen, a German chemist at the time. In 1867, Menjiev returned to St. Petersburg and served as a professor of chemistry at the university [9].

One day in the spring of 1867, Menjiev stayed at home because of poor weather, so he had to take the opportunity to continue writing a new textbook called "Chemical Principles". He does not know how to show and the number of elements and attributes of the number of arranges. Therefore, he wrote the names of each element on a card, and some attributes of the corresponding elements were marked next to him, as well as oxides and hydrogen. Then, he began to arrange cards in various ways to find a mode: placing elements with same -oriented videos in horizontal row, and arranging elements in an atomic quantity. Suddenly, he found a very distinctive arrangement. He wrote down the result on the back of an old envelope, and people can still see this envelope in St. Petersburg today. [10]

In 1867, the original element cycle table of Menjetlef

Next, Monetlev invented a more concise version. He arranged horizontally from the seven elements of lithium to fluoride in the order of increasing atomic weight [11], and then the 7 elements from sodium to chlorine were also arranged in the same way. As a result, the periodicity appears: in the column, two elements with similar chemical properties are next to each other. In the 7 columns, the main chemical price of the first column element is 1, the main offer of the next column element is 2, and then separate separately, respectively, and then separately separate, respectively It is 3, 4, 3, and 1. Next, Menjiev quickly discovered that if the form is flipped, the exchange and columns will be clearer. We can now identify this result, although many new elements have been filled in today's form.

The element table has a total of 8 columns, or it is called 8 cycles. During a large improvement work in 1870, Menjiev distributed the 63 known elements into 12 lines. Starting from hydrogen, ending with uranium, each element was placed in a row with similar chemical properties. And arrange the sequence of atomic quantity.

The results displayed by Menglev's form have an intuitive major contribution, that is, predict the existence of new elements. He did not put all known elements in a complete element cycle table like everyone else. If it was Aristotle, he would definitely do that. Menjiev believes that if the periodic table has a logical structure, it means that there may be blank on the table. He speculated that the new elements will fill these gaps, and the periodicity of the table can predict the density of atomic and atomic. Under boron, aluminum, and silicon, he speculated that three "unlimited" elements were named "boron -like", "aluminum" and "silicon" [12]. These three elements were discovered one after another, and their atomic quantity and density were consistent with the predictions of Monetlev: "aluminum" was discovered in Paris, France in 1875, called gallium (France in Gallium, France in Latin); "Boron -like" was discovered in Upsra, Sweden in 1879, and was called scandium (Scandinavia in Latin); "Silicon -like" was discovered in Fleberg, Germany in 1886. Knows (German, Germany in Latin).

Menglev also predicts the new members (titanium) in the fourth group, and its atomic amount is about 180. This element was finally discovered at the University of Copenhagen, Denmark in 1923. Atomic volume was 178.5, named HAFNIUM, Copenhagen in Latin).

In 1893, Menjiev became the head of Russian Agency and made admiration. He officially defines the composition of vodka: a molecule and two molecules of water. The molecular weight shows that the composition of vodka is 38%alcohol and 62%of water. In 1894, the legitimate standards released by the Russian Agency slightly adjusted this number to 40%of alcohol and 60%of water. This is 80%of the beauty alcohol (Proof, that is, 2 times the amount of alcohol is equal to the volume of alcohol). Regarding the great influence of Menjiev's achievements and its huge influence on scientists in the same period, Gerald Holton once had such a wonderful comparison: "This is like a book administrator who puts all books all books Put it into a bunch, weigh them one by one, and discharge these books on different racks according to the order of weight. Then, he suddenly found that the first book on each shelf is about art, and the second book is about philosophy. The third book is about science, the fourth book is about the economy, and so on. Our book administrator may not understand the inherent principles of these rules. However, once the order of the book on one of the books is found 'Art -Science -Economy', he will leave a blank in the middle of art books and science books, and start looking for the appropriate philosophical book that is lost. "[13]

We can see the periodicity of the element table from a attribute of the element, such as dividing the atomic volume with the atomic volume. This was the earliest discovered by Julius Meyer in 1870 [14]. Alkaline metal appears at the top of the chart.

Menglev never claimed that he understood the structure and periodic meaning of this table. This is a great leap in intuitive. He believes that these elements have an inherent symmetrical structure, but they have never thought that their forms are still a convenient retrieval tool, and finally make him make dramatic discoveries and predictions. Although Monetlef failed to find the laws of these elements in front of him, he knew that this watch would help others to complete it.

The modern version of this cycle table [15] is divided into 7 lines (cycles), and each row is placed with 2, 8, 8, 18, 18, 32, 32 elements. This mode can be understood after people discover the quantum theory of atoms. Electronic quantum waves to the essence of the essence means that only an integer wavelength can make the electrons "loaded" on the orbit around. The increase in the number of elements per line of the cycle table reflects the increase in the number of electrons in the orbit of the atomic nucleus of each atom. Quantum mechanics allows the inner orbit (called the shell) contains two electrons, followed by 6, and then 10 and 14.

In the periodic table, the number of elements in each row is the number of electrons under the orbit full of electrons, so there are 8 = 2 + 6, 18 = 2 + 6 + 10, 32 = 2 + 6 + 10 + 14. The elements in each row are arranged according to the lift of the atomic order, and in each column, the element is arranged according to the same outer electrical number, so that the modern form of the element cycle table is obtained. In each line, we regularly add electrons on the orbit until full of members, and finally obtained the inertia (that is, not lively) gas at the far right of the element cycle table. Then, we turn on the next line and fill the next level. It is worth mentioning that Menjiev has found this model before the electron and protons were discovered. He studied atomic quantity (determined by the number of proton in the element atomic nucleus) and the combined price (determined by the completeness of the electrons on the orbit), and found the essence of these two chemical properties in this simple method.

Today, Menjetv's element tables appear on the walls of each chemical laboratory around the world [16]. It seems that his mother's decision was right.

Menjiev's element cycle table. This is the first edition element cycle table of Russian chemist Menjiev, printed in 1869. He left a blank for new elements in the table. Scientists later discovered these elements, which proved Menjetv's speculation. The elements listed in this version are represented by chemical symbols, sorted by atomic measurement, but the complete element sorting has not appeared. In the final edition of 1871, atomic arrangement is the column or group that we know today.

Annotation

[1] Emsley J. Nature ’s Building Blocks. Oxford: Oxford up, 2003: 527.

[2] Lavoisier a. Traitéélémentaire de Chimie. 1789. This is the promotion textbook for new chemistry, which has played an important role in chemical education for many years.

[3] This is reminiscent of the modern definition of basic particles. Of course, Lavison did not know the internal structure of the atom: the proton and neutron composed of quarks were composed of the nucleus, and the latter was surrounded by electronics.

[4]BERZELIUS J J. “Essay on the Cause of Chemical Proportions, and on Some Circumstances Relating to Them: Together with a Short and Easy Method of Expressing Them”. Annals of Philosophy. 181(32): 443-454. Annals of Philosophy. 18 (143): 51-52, 93-106, 244-255, 353-364. REPRODUCED in D. M. Knight (ED.). In London, Beltius listened to Dalton's speech at the Royal Academy of Sciences and discussed it, thereby learning about Dalton's research.

[6] Formula shows the combination of copper sulfate (CUSO4) and hydrochloric acid (HCL) to obtain sulfuric acid (H2SO4) and copper chloride (CUCL2).

[7] Among them, Yilius Miya's research may be the most noteworthy. In 1868, he drew the atomic volume and atomic diagram of 49 elements and found periodic changes. He prepared a paper for friends to comment, but unfortunately, the friend responded to slow and failed to complete. As a result, Monetlev published a more comprehensive version before Mayer.

[8] In 1815, British chemist William Prout designed a detailed list, all of which were made of hydrogen. In the 19th century, people called the Platt hypothesis.

[9] POSIN D Q. Mendeleyev: The Story of a Great Scientist. New York: McGraw-Hill, 1948.

[10] It can be seen at the Menylv Museum and Archives at the St. Petersburg National University.

[11] Hydrogen has been excluded due to its unique properties, and rare gases (such as salamander) have not yet been discovered.

[12] In Greek, the prefix EKA means "follow".

[13] Holton G. IntRoduction to Concepts and theories in Physical Science. 2nd Rev. Ed with s. Brush. Princeton up, 1985: 337.

[14] The volume of the atomic volume of the solid and liquid matter is equal to the density of the atomic volume.

[15] Don't forget that there may still be an unavailable element that may not be found. These elements are unstable and only have a short time.

[16] Polima Levy's masterpiece "LEVI P. The Periodic Table. London: Michael Joseph, 1985) tells the author's own unique experience in his extraordinary life. He is both an industrial chemist and a Survivor of the Nazi concentration camp. Different chapters describe different events and characters, and each chapter is named after an element. For example, a well -known Italian celestial physicist, the late Nicolò Dallaporta as a young teaching assistant in a chapter called "Potassium". This chapter tells The Riyaster Incident in 1941. In the 1980s, I met Dala Porta. He and my mentor Dennis Sciama are all co -executives of the Italian International Institute (Sissa). Therefore, I was fortunate to confirm that Dala Polta was as charming and friendly as the young man that Levi met 40 years ago. I even discovered that Dala Porta was nicknamed "potassium" by some Italians because he played an important role in Levi's masterpiece. Levi once said that when suffering and torture during the war, seriously studying the element cycle table was an important psychological comfort. He knew that when the perpetrators turned black and white and attempted to tampering with human ethical standards, they could not change the facts in the element cycle table -there is a cornerstone of absolute truth, no one can shake.

This article is reprinted from WeChat public account: Hui Pu (ID: FANPU2019) Author: John D. Barrow

Reprinted content only represents the author's point of view

It does not represent the high energy office of the Chinese Academy of Sciences

Edit: Liu Yi

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