Technetium. I.A. Leenson. Where does your name come from? Where do the names of chemical elements come from?

In 1925, sensational reports appeared on the pages of chemical journals about the discovery of a new element included in the seventh group of the periodic table. The element was named "masurium". Listen to the name: ma-zu-ri-y. Something in tune with the mazurka - the brilliant, cheerful Polish national dance that received its name in the 19th century. famous in all European countries, can be heard in the name of the element. However, the German chemists Walter Noddack and Ida Take (who later became Ida Noddack) named the newly discovered element not in honor of the mazurka - a dance that came out of the Mazovia voivodeship. It was named Masuria in honor of the southern part of the districts of Gumbinnen and Königsberg in East Prussia, which had long been inhabited by Polish peasants.

The claim to discover a new element also turned out to be unfounded. Research has shown that the authors were hasty with their messages - various admixtures of other already known elements were mistaken for a new element.

The real discovery, or rather, the obtaining of an element occupying number 43 in D.I. Mendeleev’s periodic table, was carried out by the Italian scientist E. Segre and his assistant K. Perrier in 1937. The new element was created by “shelling” molybdenum with deuterons - nuclei of a heavy isotope of hydrogen, accelerated in a cyclotron.

Obtained artificially, the new element was named technetium in honor of the technical progress of the 20th century, as the brainchild of this progress. "Technikos" means "artificial" in Greek.

In 1950, the total amount of technetium on the entire globe was... one milligram. Currently, technetium is obtained as a waste product from the operation of nuclear reactors.

The technetium content in uranium fission products reaches 6%. Now, technetium, a man-made element, is not uncommon. By 1958, Parker and Martin, employees of the Oak Ridge National Laboratory, had at their disposal several grams of technetium, the compounds of which were widely used in studying the mechanism of corrosion and the action of inhibitors - substances that delay it.

According to their own chemical properties technetium is similar to manganese and rhenium. It looks more like rhenium. The density of technetium is 11.5. Unlike rhenium, technetium is more resistant to chemical reagents. The empty cell in the periodic table of elements with the inscription “ecamanganese”, the existence of which D.I. Mendeleev predicted back in 1870, is now filled with an element whose properties exactly correspond to those predicted.

However, there is no technetium on Earth! The fact is that, being a radioactive element, it does not have long-lived isotopes. The most stable isotope of technetium has a half-life of no more than 250,000 years. And since the age of the Earth is several billion years old, the technetium that originally existed on Earth has long since outlived its usefulness and should now be considered an “extinct” element. However, technetium has been found on the Sun and some stars spectroscopically, which indicates its synthesis during the evolution of stars.

Nuclide table General information Name, symbol Technetium 99, 99Tc Neutrons 56 Protons 43 Nuclide properties Atomic mass 98.9062547(21) ... Wikipedia

TECHNETIUM- (symbol Tc), silver-gray metal, RADIOACTIVE ELEMENT. It was first obtained in 1937 by bombarding MOLYBDENUM nuclei with deuterons (the nuclei of DEUTERium atoms) and was the first element synthesized in a cyclotron. Technetium found in products... ... Scientific and technical encyclopedic dictionary

TECHNETIUM- artificially synthesized radioactive chemical. element, symbol Tc (lat. Technetium), at. n. 43, at. m. 98.91. T. is obtained in fairly large quantities from the fission of uranium 235 in nuclear reactors; managed to obtain about 20 isotopes of T. One of... ... Big Polytechnic Encyclopedia

TECHNETIUM- (Technetium), Tc, artificial radioactive element of group VII of the periodic table, atomic number 43; metal. Obtained by Italian scientists C. Perrier and E. Segre in 1937 ... Modern encyclopedia

TECHNETIUM- (lat. Technetium) Tc, chemical element of group VII of the periodic system, atomic number 43, atomic mass 98.9072. Radioactive, the most stable isotopes are 97Tc and 99Tc (half-lives are 2.6.106 and 2.12.105 years, respectively). First… … Big Encyclopedic Dictionary

TECHNETIUM- (lat. Technetium), Tc radioact. chem. element of group VII is periodic. Mendeleev's system of elements, at. number 43, the first of the artificially obtained chemicals. elements. Naib. long-lived radionuclides 98Tc (T1/2 = 4.2·106 years) and available in noticeable amounts... ... Physical encyclopedia

technetium- noun, number of synonyms: 3 metal (86) ecamanganese (1) element (159) Dictionary of synonyms ... Synonym dictionary

Technetium- (Technetium), Tc, artificial radioactive element of group VII of the periodic table, atomic number 43; metal. Obtained by Italian scientists C. Perrier and E. Segre in 1937. ... Illustrated Encyclopedic Dictionary

technetium- I; m. [from Greek. technetos artificial] Chemical element (Tc), a silver-gray radioactive metal obtained from nuclear waste. ◁ Technetium, oh, oh. * * * technetium (lat. Technetium), a chemical element of group VII... ... encyclopedic Dictionary

Technetium- (lat. Technetium) Te, radioactive chemical element of group VII of the periodic system of Mendeleev, atomic number 43, atomic mass 98, 9062; metal, malleable and ductile. The existence of element with atomic number 43 was... ... Great Soviet Encyclopedia

Books

• Elements. A wonderful dream of Professor Mendeleev, Kuramshin Arkady Iskanderovich. What chemical element is named after goblins? How many times has technetium been “discovered”? What are “transfermium wars”? Why once even pundits confused manganese with magnesium and lead with... Buy for 567 RUR
• Elements are a wonderful dream of Professor Mendeleev, Kuramshin A.. Which chemical element is named after goblins? How many times has technetium been “discovered”? What are “transfermium wars”? Why did even pundits once confuse manganese with magnesium and lead with...

Technetium (Latin Technetium, Tc; read “technetium”) is the first artificially produced radioactive chemical element, atomic number 43. The term is derived from the Greek “technetos” - artificial. Technetium has no stable isotopes. The longest-lived radioisotopes: 97 Tc (T 1/2 is 2.6 10 6 years, electron capture), 98 Tc (T 1/2 is 1.5 10 6 years), 99 Tc (T 1/2 is 2 , 12·10 5 years). The short-lived nuclear isomer 99m Tc (T 1/2 is equal to 6.02 hours) is of practical importance.

The configuration of the two outer electronic layers is 4s 2 p 6 d 5 5s 2. Oxidation states from -1 to +7 (valency I-VII); most stable +7. Located in group VIIB in the 5th period of the periodic table of elements. The radius of the atom is 0.136 nm, the Tc 2+ ion is 0.095 nm, the Tc 4+ ion is 0.070 nm, the Tc 7+ ion is 0.056 nm. Successive ionization energies are 7, 28, 15, 26, 29, 54 eV. Electronegativity according to Pauling 1.9.

When creating the periodic table, D.I. Mendeleev left an empty cell in the table for technetium, a heavy analogue of manganese (“ecamanganese”). Technetium was obtained in 1937 by C. Perrier and E. Segre by bombarding a molybdenum plate with deuterons. In nature, technetium is found in negligible quantities in uranium ores, 5·10 -10 g per 1 kg of uranium. Spectral lines of technetium have been found in the spectra of the Sun and other stars.

Technetium is isolated from a mixture of fission products 235 U - waste from the nuclear industry. When reprocessing spent nuclear fuel, technetium is extracted using ion exchange, extraction, and fractional precipitation methods. Technetium metal is obtained by reducing its oxides with hydrogen at 500°C. World production of technetium reaches several tons per year. For research purposes, short-lived radionuclides of technetium are used: 95m Tc( T 1/2 =61 days), 97m Tc (T 1/2 =90 days), 99m Tc.

Technetium is a silver-gray metal, with a hexagonal lattice, A=0.2737 nm, c= 0.4391 nm. Melting point 2200°C, boiling point 4600°C, density 11.487 kg/dm3. The chemical properties of technetium are similar to rhenium. Values ​​of standard electrode potentials: Tc(VI)/Tc(IV) pairs 0.83 V, Tc(VII)/Tc(VI) pairs 0.65 V, Tc(VII)/Tc(IV) pairs 0.738 V.

When Tc burns in oxygen, yellow higher acidic oxide Tc 2 O 7 is formed. Its solution in water is technetic acid HTcO 4. When it evaporates, dark brown crystals form. Salts of technical acid - pertechnates (sodium pertechnate NaTcO 4, potassium pertechnate KTcO 4, silver pertechnate AgTcO 4). During the electrolysis of a solution of technical acid, TcO 2 dioxide is released, which, when heated in oxygen, turns into Tc 2 O 7.

Interacting with fluorine, Tc forms golden-yellow crystals of technetium hexafluoride TcF 6 mixed with TcF 5 pentafluoride. Technetium oxyfluorides TcOF 4 and TcO 3 F were obtained. Chlorination of technetium gives a mixture of TcCl 6 hexachloride and TcCl 4 tetrachloride. Technetium oxychlorides TcO 3 Cl and TcOCl 3 were synthesized. Known

Hydrogen has been known as combustible (flammable) air for quite some time. It was obtained by the action of acids on metals; the combustion and explosions of explosive gas were observed by Paracelsus, Boyle, Lemery and other scientists of the 16th - 18th centuries. With the spread of the phlogiston theory, some chemists tried to produce hydrogen as "free phlogiston." Lomonosov's dissertation "On metallic luster" describes the production of hydrogen by the action of "acid alcohols" (for example, "hydrochloric alcohol", i.e. of hydrochloric acid) for iron and other metals; Russian scientist first(1745) hypothesized that hydrogen (“flammable vapor” - vapor inflammabilis) is phlogiston. Cavendish, who studied the properties of hydrogen in detail, put forward a similar hypothesis in 1766. He called hydrogen “inflammable air” obtained from “metals” (inflammable air from metals), and believed, like all phlogisticians, that when dissolved in acids the metal loses your phlogiston. Lavoisier, who in 1779 studied the composition of water through its synthesis and decomposition, called hydrogen Hydrogine (hydrogen), or Hydrogene (hydrogen), from the Greek. hydro - water and gaynome - I produce, I give birth.

The Nomenclature Commission of 1787 adopted the word production Hydrogene from gennao - I give birth. In Lavoisier's Table of Simple Bodies, hydrogen is mentioned among the five (light, heat, oxygen, nitrogen, hydrogen) "simple bodies belonging to all three kingdoms of nature and which should be considered as elements of bodies"; As an old synonym for the name Hydrogene, Lavoisier calls flammable gas (gaz inflammable), the base of flammable gas. In Russian chemical literature of the late 18th and early 19th centuries. There are two kinds of names for hydrogen: phlogistic (combustible gas, combustible air, ignitable air, ignitable air) and antiphlogistic (water-creating creature, water-creating being, water-creating gas, hydrogen gas, hydrogen). Both groups of words are translations of the French names for hydrogen.

Hydrogen isotopes were discovered in the 1930s and quickly became great importance in science and technology. At the end of 1931, Urey, Brekwedd and Murphy examined the residue after long-term evaporation of liquid hydrogen and discovered heavy hydrogen with an atomic weight of 2. This isotope was called deuterium (D) from the Greek. - another, second. Four years later, an even heavier isotope of hydrogen, 3H, was discovered in water subjected to long-term electrolysis, which was called tritium (Tritium, T), from the Greek. - third.
Helium, Helium, He (2)

In 1868, the French astronomer Jansen observed a total solar eclipse in India and spectroscopically studied the chromosphere of the sun. He discovered a bright yellow line in the spectrum of the sun, which he designated D3, which did not coincide with the yellow D line of sodium. At the same time, the same line in the spectrum of the sun was seen by the English astronomer Lockyer, who realized that it belonged to an unknown element. Lockyer, together with Frankland, for whom he was then working, decided to name the new element helium (from the Greek helios - sun). Then a new yellow line was discovered by other researchers in the spectra of “terrestrial” products; Thus, in 1881, the Italian Palmieri discovered it while studying a gas sample taken in the crater of Vesuvius. The American chemist Hillebrand, studying uranium minerals, found that they emit gases when exposed to strong sulfuric acid. Hillebrand himself believed that it was nitrogen. Ramsay, who paid attention to Hillebrand's message, subjected to spectroscopic analysis the gases released when the mineral kleveite was treated with acid. He discovered that the gases contained nitrogen, argon, and an unknown gas that produced a bright yellow line. Lacking a good enough spectroscope, Ramsay sent samples of the new gas to Crookes and Lockyer, who soon identified the gas as helium. Also in 1895, Ramsay isolated helium from a mixture of gases; it turned out to be chemically inert, like argon. Soon after this, Lockyer, Runge and Paschen made a statement that helium consists of a mixture of two gases - orthohelium and parahelium; one of them gives a yellow spectrum line, the other a green one. They proposed to call this second gas asterium (Asterium) from the Greek - star. Together with Travers, Ramsay tested this statement and proved that it was wrong, since the color of the helium line depends on the gas pressure.
Lithium, Lithium, Li (3)

When Davy carried out his famous experiments on the electrolysis of alkaline earths, no one suspected the existence of lithium. Lithium alkaline earth was discovered only in 1817 by a talented analytical chemist, one of Berzelius' students, Arfvedson. In 1800, the Brazilian mineralogist de Andrada Silva, making a scientific trip to Europe, found two new minerals in Sweden, which he named petalite and spodumene, and the first of them was rediscovered a few years later on the island of Ute. Arfvedson became interested in petalite, carried out a complete analysis of it and discovered an initially inexplicable loss of about 4% of the substance. Repeating the analyzes more carefully, he established that petalite contained “a flammable alkali of a hitherto unknown nature.” Berzelius proposed to call it lithion, since this alkali, unlike potassium and soda, was first found in the “kingdom of minerals” (stones); This name is derived from the Greek - stone. Arfvedson later discovered lithium earth, or lithine, in several other minerals, but his attempts to isolate the free metal were unsuccessful. Very a small amount of Lithium metal was obtained by Davy and Brande by electrolysis of alkali. In 1855, Bunsen and Matthessen developed an industrial method for producing lithium metal by electrolysis of lithium chloride. In Russian chemical literature of the early 19th century. names are found: lithion, litin (Dvigubsky, 1826) and lithium (Hess); lithium earth (alkali) was sometimes called litina.
Beryllium, Be (4)

Beryllium-containing minerals ( gems) - beryl, emerald, emerald, aquamarine, etc. - have been known since ancient times. Some of them were mined on the Sinai Peninsula back in the 17th century. BC e. The Stockholm papyrus (3rd century) describes methods for making counterfeit stones. The name beryl is found in Greek and Latin (Beryll) ancient writers and in ancient Russian works, for example in the “Svyatoslav's Collection” of 1073, where beryl appears under the name virullion. Study chemical composition precious minerals of this group began, however, only at the end of the 18th century. with the onset of the chemical-analytical period. The first analyzes (Klaproth, Bindheim, etc.) did not find anything special in beryl. At the end of the 18th century. the famous mineralogist Abbot Gahuy drew attention to the complete similarity of the crystal structure of beryl from Limoges and emerald from Peru. Vaukelin carried out a chemical analysis of both minerals (1797) and discovered in both a new earth, different from alumina. Having received the salts of the new land, he found that some of them have a sweet taste, which is why he named the new land glucina (Glucina) from the Greek. - sweet. The new element contained in this earth was appropriately named Glucinium. This name was used in France in the 19th century; there was even a symbol - Gl. Klaproth, being an opponent of naming new elements based on the random properties of their compounds, proposed calling glucinium beryllium, pointing out that compounds of other elements also have a sweet taste. Beryllium metal was first prepared by Wöhler and Bussy in 1728 by reducing beryllium chloride with potassium metal. Let us note here the outstanding research of the Russian chemist I.V. Avdeev on the atomic weight and composition of beryllium oxide (1842). Avdeev established the atomic weight of beryllium as 9.26 (modern 9.0122), while Berzelius took it to be 13.5, and the correct formula for the oxide.

There are several versions about the origin of the name of the mineral beryl, from which the word beryllium is derived. A. M. Vasiliev (according to Diergart) cites the following opinion of philologists: the Latin and Greek names of beryl can be compared with the Prakrit veluriya and Sanskrit vaidurya. The latter is the name of a certain stone, and is derived from the word vidura (very far), which seems to mean some country or mountain. Müller offered another explanation: vaidurya came from the original vaidarya or vaidalya, and the latter from vidala (cat). In other words, vaidurya roughly means "cat's eye". Rai indicates that in Sanskrit topaz, sapphire and coral were considered cat's eye. The third explanation is given by Lippmann, who believes that the word beryl meant some kind of northern country(where the precious stones came from) or the people. Elsewhere Lippmann notes that Nicholas of Cusa wrote that the German Brille (spectacles) comes from the Barbarian Latin berillus. Finally, Lemery, explaining the word beryl (Beryllus), points out that Berillus, or Verillus, means "man's stone."

In Russian chemical literature of the early 19th century. Glucina was called sweet earth, sweet earth (Severgin, 1815), sweet earth (Zakharov, 1810), glutina, glycine, the base of glycine earth, and the element was called wisterium, glycinite, glycium, sweet earth, etc. Giese proposed the name beryllium (1814). Hess, however, stuck to the name Glitium; it was also used as a synonym by Mendeleev (1st ed. “Fundamentals of Chemistry”).
Bor, Borum, V (5)

Natural boron compounds (English Boron, French Bore, German Bor), mainly impure borax, have been known since the early Middle Ages. Under the names Tinkal, Tinkar, Attinkar (Tinkal, Tinkar, Attinkar) borax was imported to Europe from Tibet; it was used for soldering metals, especially gold and silver. In Europe, tinkal was more often called borax (Borax) from Arabic word bauraq and Persian - burah. Sometimes borax, or boraco, meant various substances, such as soda (nitrone). Ruland (1612) calls borax chrysocolla, a resin capable of “gluing” gold and silver. Lemery (1698) also calls borax “glue of gold” (Auricolla, Chrisocolla, Gluten auri). Sometimes borax meant something like “bridle of gold” (capistrum auri). In Alexandrian, Hellenistic and Byzantine chemical literature, borah and borakhon, as well as in Arabic (bauraq) generally meant alkali, for example bauraq arman (Armenian borak), or soda, later they began to call borax.

In 1702, Homberg, by calcining borax with iron sulfate, obtained “salt” (boric acid), which became known as “Homberg’s soothing salt” (Sal sedativum Hombergii); this salt is widely used in medicine. In 1747, Baron synthesized borax from “soothing salt” and natron (soda). However, the composition of borax and “salt” remained unknown until the beginning of the 19th century. The Chemical Nomenclature of 1787 contains the name horacique acid (boric acid). Lavoisier in his “Table of Simple Bodies” cites radical boracique. In 1808, Gay-Lussac and Thénard succeeded in isolating free boron from boric anhydride by heating the latter with potassium metal in a copper tube; they proposed to name the element boron (Bora) or boron (Bore). Davy, who repeated the experiments of Gay-Lussac and Thénard, also obtained free boron and named it boracium. Later, the British shortened this name to Boron. In Russian literature, the word borax is found in prescription collections of the 17th - 18th centuries. At the beginning of the 19th century. Russian chemists called boron borax (Zakharov, 1810), buron (Strakhov, 1825), boric acid base, buracin (Severgin, 1815), boria (Dvigubsky, 1824). The translator of Giese's book called boron burium (1813). In addition, there are names such as drill, harrow, buronite, etc.
Carbon, Carboneum, C (6)

Carbon (English Carbon, French Carbone, German Kohlenstoff) in the form of coal, soot and soot has been known to mankind since time immemorial; about 100 thousand years ago, when our ancestors mastered fire, they dealt with coal and soot every day. Probably, very early people became acquainted with allotropic modifications of carbon - diamond and graphite, as well as fossil coal. It is not surprising that the combustion of carbon-containing substances was one of the first chemical processes to interest man. Since the burning substance disappeared when consumed by fire, combustion was considered a process of decomposition of the substance, and therefore coal (or carbon) was not considered an element. The element was fire - a phenomenon accompanying combustion; In ancient teachings about the elements, fire usually appears as one of the elements. At the turn of the XVII - XVIII centuries. The phlogiston theory arose, put forward by Becher and Stahl. This theory recognized the presence in each combustible body of a special elementary substance - a weightless fluid - phlogiston, which evaporates during the combustion process. Since when a large amount of coal is burned, only a little ash remains, phlogistics believed that coal was almost pure phlogiston. This is what explained, in particular, the “phlogisticating” effect of coal - its ability to restore metals from “limes” and ores. Later phlogistics - Reaumur, Bergman and others - already began to understand that coal is an elementary substance. However, “clean coal” was first recognized as such by Lavoisier, who studied the process of combustion of coal and other substances in air and oxygen. In the book "Method of Chemical Nomenclature" (1787) by Guiton de Morveau, Lavoisier, Berthollet and Fourcroix, the name "carbon" (carbone) appeared instead of the French "pure coal" (charbone pur). Under the same name, carbon appears in the “Table of Simple Bodies” in Lavoisier’s “Elementary Textbook of Chemistry.” In 1791, the English chemist Tennant was the first to obtain free carbon; he passed phosphorus vapor over calcined chalk, resulting in the formation of calcium phosphate and carbon. It has been known for a long time that diamond burns without leaving a residue when heated strongly. Back in 1751, the French king Francis I agreed to give diamond and ruby ​​for combustion experiments, after which these experiments even became fashionable. It turned out that only diamond burns, and ruby ​​(aluminum oxide with an admixture of chromium) can withstand prolonged heating at the focus of the ignition lens without damage. Lavoisier set new experience on burning a diamond with a large incendiary machine, and came to the conclusion that the diamond was crystalline carbon. The second allotrope of carbon - graphite - in the alchemical period was considered a modified lead luster and was called plumbago; It was only in 1740 that Pott discovered the absence of any lead impurity in graphite. Scheele studied graphite (1779) and, being a phlogistician, considered it a special kind of sulfur body, a special mineral coal containing bound “aerial acid” (CO2) and a large amount of phlogiston.

Twenty years later, Guiton de Morveau turned diamond into graphite and then into carbonic acid by careful heating.

The international name Carboneum comes from the Latin. carbo (coal). This word is of very ancient origin. It is compared with cremare - to burn; root сar, cal, Russian gar, gal, gol, Sanskrit sta means to boil, cook. The word "carbo" is associated with the names of carbon in other European languages ​​(carbon, charbone, etc.). German Kohlenstoff comes from Kohle - coal (Old German kolo, Swedish kylla - to heat). Old Russian ugorati, or ugarati (to burn, scorch) has the root gar, or mountains, with a possible transition to gol; coal in Old Russian yugal, or coal, of the same origin. The word diamond (Diamante) comes from the ancient Greek - indestructible, unyielding, hard, and graphite from the Greek - I write.

At the beginning of the 19th century. the old word coal in Russian chemical literature was sometimes replaced by the word “carbonate” (Scherer, 1807; Severgin, 1815); Since 1824, Soloviev introduced the name carbon.

Nitrogen, Nitrogenium, N (7)

Nitrogen (English Nitrogen, French Azote, German Stickstoff) was discovered almost simultaneously by several researchers. Cavendish obtained nitrogen from the air (1772) by passing it through hot coal and then through an alkali solution to absorb carbon dioxide. Cavendish did not give a special name to the new gas, referring to it as mephitic air (Air mephitic from the Latin mephitis - suffocating or harmful evaporation of the earth). Priestley soon discovered that if a candle burns in the air for a long time or an animal (a mouse) is present, then such air becomes unsuitable for breathing. Officially, the discovery of nitrogen is usually attributed to Black’s student, Rutherford, who in 1772 published a dissertation (for the degree of Doctor of Medicine) - “On the fixed air, otherwise called asphyxiating,” where some of the chemical properties of nitrogen were first described. During these same years, Scheele obtained nitrogen from atmospheric air in the same way as Cavendish. He called the new gas “spoiled air” (Verdorbene Luft). Since passing air through hot coal was considered by phlogistic chemists to be phlogisticating it, Priestley (1775) called nitrogen phlogisticated air. Cavendish also spoke earlier about phlogistication of air in his experience. Lavoisier in 1776 - 1777 studied in detail the composition of atmospheric air and found that 4/5 of its volume consists of asphyxiating gas (Air mofette - atmospheric mofette, or simply Mofett). The names of nitrogen - phlogisticated air, mephic air, atmospheric mofett, spoiled air and some others - were used before the recognition of a new chemical nomenclature in European countries, that is, before the publication of the famous book “The Method of Chemical Nomenclature” (1787).

The compilers of this book - members of the nomenclature commission of the Paris Academy of Sciences - Guiton de Morveau, Lavoisier, Berthollet and Fourcroix - accepted only a few new names for simple substances, in particular, the names “oxygen” and “hydrogen” proposed by Lavoisier. When choosing a new name for nitrogen, the commission, based on the principles of the oxygen theory, found itself in difficulty. As is known, Lavoisier proposed giving simple substances names that would reflect their basic chemical properties. Accordingly, this nitrogen should be given the name “nitric radical” or “nitrate radical”. Such names, writes Lavoisier in his book "Principles of Elementary Chemistry" (1789), are based on the old terms nitre or saltpeter, accepted in the arts, in chemistry and in society. They would be quite suitable, but it is known that nitrogen is also the base of the volatile alkali (ammonia), as Berthollet had recently discovered. Therefore, the name radical, or base of nitrate acid, does not reflect the basic chemical properties of nitrogen. Isn't it better to dwell on the word nitrogen, which, according to members of the nomenclature commission, reflects the main property of the element - its unsuitability for breathing and life? The authors of chemical nomenclature proposed to derive the word nitrogen from the Greek negative prefix “a” and the word life. Thus, the name nitrogen, in their opinion, reflected its non-vitality, or lifelessness.

However, the word nitrogen was not coined by Lavoisier or his colleagues on the commission. It has been known since ancient times and was used by philosophers and alchemists of the Middle Ages to designate the “primary matter (base) of metals,” the so-called mercury of philosophers, or the double mercury of alchemists. The word nitrogen entered literature, probably in the first centuries of the Middle Ages, like many other encrypted names with a mystical meaning. It is found in the works of many alchemists, starting with Bacon (XIII century) - in Paracelsus, Libavius, Valentinus and others. Libavius ​​even points out that the word nitrogen (azoth) comes from the ancient Spanish-Arabic word azoque (azoque or azoc), meaning mercury. But it is more likely that these words appeared as a result of scribal distortions of the root word nitrogen (azot or azoth). Now the origin of the word nitrogen has been established more precisely. Ancient philosophers and alchemists considered the “primary matter of metals” to be the alpha and omega of everything that exists. In turn, this expression is borrowed from the Apocalypse, the last book of the Bible: “I am alpha and omega, beginning and end, first and last.” In ancient times and in the Middle Ages, Christian philosophers considered it proper to use only three languages ​​that were recognized as “sacred” when writing their treatises - Latin, Greek and Hebrew (the inscription on the cross at the crucifixion of Christ, according to the Gospel story, was made in these three languages). To form the word nitrogen, the initial and final letters of the alphabets of these three languages ​​were taken (a, alpha, aleph and zet, omega, tov - AAAZOT).

The compilers of the new chemical nomenclature of 1787, and above all the initiator of its creation, Guiton de Morveau, were well aware of the existence of the word nitrogen since ancient times. Morvo noted in the "Methodical Encyclopedia" (1786) the alchemical meaning of this term. After the publication of the Method of Chemical Nomenclature, opponents of the oxygen theory - phlogistics - sharply criticized the new nomenclature. Especially, as Lavoisier himself notes in his chemistry textbook, the adoption of “ancient names” was criticized. In particular, La Mettrie, publisher of the journal Observations sur la Physique, a stronghold of opponents of the oxygen theory, pointed out that the word nitrogen was used by alchemists in a different sense.

Despite this, the new name was adopted in France, as well as in Russia, replacing the previously accepted names “phlogisticated gas”, “moffette”, “moffette base”, etc.

The word formation nitrogen from Greek also caused fair comments. D. N. Pryanishnikov, in his book “Nitrogen in the life of plants and in agriculture of the USSR” (1945), quite correctly noted that word formation from Greek “raises doubts.” Obviously, Lavoisier’s contemporaries also had these doubts. Lavoisier himself in his chemistry textbook (1789) uses the word nitrogen along with the name “radical nitrique”.

It is interesting to note that later authors, apparently trying to somehow justify the inaccuracy made by the members of the nomenclature commission, derived the word nitrogen from the Greek - life-giving, life-giving, creating the artificial word “azotikos”, which is absent in Greek(Diergart, Remy, etc.). However, this way of forming the word nitrogen can hardly be considered correct, since the derivative word for the name nitrogen should have sounded “azotikon”.

The inadequacy of the name nitrogen was obvious to many of Lavoisier’s contemporaries, who fully sympathized with his oxygen theory. Thus, Chaptal, in his chemistry textbook “Elements of Chemistry” (1790), proposed replacing the word nitrogen with the word nitrogen (nitrogen) and called the gas, in accordance with the views of his time (each gas molecule was represented as surrounded by an atmosphere of caloric), “nitrogen gas” (Gas nitrogene). Chaptal motivated his proposal in detail. One of the arguments was the indication that the name meaning lifeless could, with greater justification, be given to other simple bodies (possessing, for example, strong poisonous properties). The name nitrogen, adopted in England and America, later became the basis for the international name of the element (Nitrogenium) and the symbol for nitrogen - N. In France at the beginning of the 19th century. Instead of the symbol N, the symbol Az was used. In 1800, one of the co-authors of the chemical nomenclature, Fourcroy, proposed another name - alcaligene, based on the fact that nitrogen is the “base” of the volatile alkali (Alcali volatil) - ammonia. But this name was not accepted by chemists. Let us finally mention the name nitrogen, which was used by phlogistic chemists and, in particular, Priestley, at the end of the 18th century. - septon (Septon from the French Septique - putrefactive). This name was apparently proposed by Mitchell, a student of Black who later worked in America. Davy rejected this name. In Germany since the end of the 18th century. and to this day nitrogen is called Stickstoff, which means "suffocating substance."

As for the old Russian names for nitrogen, which appeared in various works of the late 18th - early 19th centuries, they are as follows: suffocating gas, unclean gas; mofetic air (all these are translations of the French name Gas mofette), suffocating substance (translation of the German Stickstoff), phlogisticated air, extinguished, flammable air (phlogistic names are a translation of the term proposed by Priestley - Plogisticated air). Names were also used; spoiled air (translation of Scheele's term Verdorbene Luft), saltpeter, saltpeter gas, nitrogen (translation of the name proposed by Chaptal - Nitrogene), alkaligen, alkali (Fourcroy's terms translated into Russian in 1799 and 1812), septon, putrefactive agent (Septon ) etc. Along with these numerous names, the words nitrogen and nitrogen gas were also used, especially from the beginning of the 19th century.

V. Severgin in his “Guide to the most convenient understanding of foreign chemical books” (1815) explains the word nitrogen as follows: “Azoticum, Azotum, Azotozum - nitrogen, asphyxiating substance”; "Azote - Nitrogen, saltpeter"; "nitrate gas, nitrogen gas." The word nitrogen finally entered the Russian chemical nomenclature and supplanted all other names after the publication of “Foundations of Pure Chemistry” by G. Hess (1831).
Derivative names for compounds containing nitrogen are formed in Russian and other languages ​​either from the word nitrogen (nitric acid, azo compounds, etc.) or from the international name nitrogenium (nitrates, nitro compounds, etc.). The last term comes from the ancient names nitr, nitrum, nitron, which usually meant saltpeter, sometimes natural soda. Ruland's dictionary (1612) says: "Nitrum, boron (baurach), saltpeter (Sal petrosum), nitrum, among the Germans - Salpeter, Bergsalz - the same as Sal petrae."

The discovery of oxygen (English Oxygen, French Oxygene, German Sauerstoff) marked the beginning of the modern period in the development of chemistry. It has been known since ancient times that combustion requires air, but for many centuries the combustion process remained unclear. Only in the 17th century. Mayow and Boyle independently expressed the idea that the air contains some substance that supports combustion, but this completely rational hypothesis was not developed at that time, since the idea of ​​combustion as a process of combining a burning body with a certain component of the air seemed at that time, contradicting such an obvious fact as the fact that during combustion the decomposition of the burning body into elementary components takes place. It was on this basis that at the turn of the 17th century. The phlogiston theory arose, created by Becher and Stahl. With the advent of the chemical-analytical period in the development of chemistry (the second half of the 18th century) and the emergence of “pneumatic chemistry” - one of the main branches of the chemical-analytical direction - combustion, as well as respiration, again attracted the attention of researchers. The discovery of various gases and the establishment of their important role in chemical processes was one of the main incentives for the systematic studies of combustion processes undertaken by Lavoisier. Oxygen was discovered in the early 70s of the 18th century. The first report of this discovery was made by Priestley at a meeting of the Royal Society of England in 1775. Priestley, by heating red mercury oxide with a large burning glass, obtained a gas in which the candle burned more brightly than in ordinary air, and the smoldering splinter flared up. Priestley determined some of the properties of the new gas and called it daphlogisticated air. However, two years earlier, Priestley (1772) Scheele also obtained oxygen by the decomposition of mercuric oxide and other methods. Scheele called this gas fire air (Feuerluft). Scheele was able to report his discovery only in 1777. Meanwhile, in 1775, Lavoisier spoke before the Paris Academy of Sciences with a message that he had managed to obtain “the purest part of the air that surrounds us,” and described the properties of this part of the air. At first, Lavoisier called this “air” empyrean, vital (Air empireal, Air vital), the basis of vital air (Base de l'air vital). The almost simultaneous discovery of oxygen by several scientists in different countries caused controversy about priority. Priestley was especially persistent in seeking recognition as a discoverer. In essence, these disputes have not ended yet. A detailed study of the properties of oxygen and its role in the processes of combustion and the formation of oxides led Lavoisier to the incorrect conclusion that this gas is an acid-forming principle. In 1779, Lavoisier, in accordance with this conclusion, introduced a new name for oxygen - the acid-forming principle (principe acidifiant ou principe oxygine). Lavoisier derived the word oxygine, which appears in this complex name, from the Greek. - acid and “I produce.”
Fluorine, Fluorum, F (9)

Fluorine (English Fluorine, French and German Fluor) was obtained in a free state in 1886, but its compounds have been known for a long time and were widely used in metallurgy and glass production. The first mention of fluorite (CaF2) under the name fluorspar (Fliisspat) dates back to the 16th century. One of the works attributed to the legendary Vasily Valentin mentions stones painted in various colors - flux (Fliisse from Latin fluere - to flow, pour), which were used as fluxes in the smelting of metals. Agricola and Libavius ​​write about this. The latter introduces special names for this flux - fluorspar (Flusspat) and mineral fluors. Many authors of chemical and technical works of the 17th and 18th centuries. describe different types fluorspar. In Russia these stones were called fin, spalt, spat; Lomonosov classified these stones as selenites and called them spar or flux (crystal flux). Russian craftsmen, as well as collectors of mineral collections (for example, in the 18th century, Prince P.F. Golitsyn) knew that some types of spar when heated (for example, in hot water) glow in the dark. However, Leibniz, in his history of phosphorus (1710), mentions thermophosphorus (Thermophosphorus) in this regard.

Apparently, chemists and artisan chemists became acquainted with hydrofluoric acid no later than the 17th century. In 1670, the Nuremberg artisan Schwanhard used fluorspar mixed with sulfuric acid to etch patterns on glass goblets. However, at that time the nature of fluorspar and hydrofluoric acid was completely unknown. It was believed, for example, that silicic acid had a pickling effect in the Schwanhard process. This erroneous opinion was eliminated by Scheele, who proved that when fluorspar reacts with sulfuric acid, silicic acid is obtained as a result of the corrosion of a glass retort by the resulting hydrofluoric acid. In addition, Scheele established (1771) that fluorspar is a combination of calcareous earth with a special acid, which was called “Swedish acid”. Lavoisier recognized the hydrofluoric acid radical as a simple body and included it in his table of simple bodies. In more or less pure form hydrofluoric acid was obtained in 1809 by Gay-Lussac and Thénard by distilling fluorspar with sulfuric acid in a lead or silver retort. During this operation, both researchers were poisoned. The true nature of hydrofluoric acid was established in 1810 by Ampere. He rejected Lavoisier's opinion that hydrofluoric acid should contain oxygen, and proved the analogy of this acid with hydrochloric acid. Ampere reported his findings to Davy, who had recently established the elemental nature of chlorine. Davy completely agreed with Ampere's arguments and spent a lot of effort on obtaining free fluorine by electrolysis of hydrofluoric acid and other ways. Taking into account the strong corrosive effect of hydrofluoric acid on glass, as well as on plant and animal tissues, Ampere proposed calling the element contained in it fluorine (Greek - destruction, death, pestilence, plague, etc.). However, Davy did not accept this name and proposed another - Fluorine, by analogy with the then name of chlorine - Chlorine, both names are still used in English language. The name given by Ampere has been preserved in Russian.

Numerous attempts to isolate free fluorine in the 19th century. did not lead to successful results. Only in 1886 did Moissan manage to do this and obtain free fluorine in the form of a yellow-green gas. Since fluorine is an unusually aggressive gas, Moissan had to overcome many difficulties before he found a material suitable for equipment in experiments with fluorine. The U-tube for electrolysis of hydrofluoric acid at minus 55oC (cooled by liquid methyl chloride) was made of platinum with fluorspar plugs. After the chemical and physical properties of free fluorine were studied, it found wide application. Now fluorine is one of the most important components in the synthesis of a wide range of organofluorine substances. In Russian literature of the early 19th century. fluorine was called differently: hydrofluoric acid base, fluorin (Dvigubsky, 1824), fluoricity (Iovsky), fluor (Shcheglov, 1830), fluor, fluorine, fluoride. Hess introduced the name fluorine in 1831.
Neon, Neon, Ne (10)

This element was discovered by Ramsay and Travers in 1898, a few days after the discovery of krypton. Scientists have sampled the first bubbles of gas produced by the evaporation of liquid argon and found that the spectrum of this gas indicates the presence of a new element. Ramsay talks about the choice of name for this element:

“When we first looked at its spectrum, my 12-year-old son was there.
“Father,” he said, “what is the name of this beautiful gas?”
“It hasn’t been decided yet,” I replied.
- He's new? - the son was curious.
“Newly discovered,” I objected.
- Why not call him Novum, father?
“That doesn’t apply because novum is not a Greek word,” I replied. - We'll call it neon, which means new in Greek.
This is how the gas got its name."
Author: Figurovsky N.A.
Chemistry and Chemists No. 1 2012

To be continued...

Segre was carrying a piece of irradiated molybdenum across the ocean... But there was no confidence that a new element would be discovered in it, and there could not be. There were “for” and “against”.

Falling on the molybdenum plate, fast deuteron penetrates quite deeply into its thickness. In some cases, one of the deuterons can merge with the nucleus of a molybdenum atom. For this, first of all, it is necessary that the energy of the deuteron be sufficient to overcome the forces of electrical repulsion. And this, by the way, means that the cyclotron must accelerate the deuteron to a speed of about 15 thousand km/sec. The compound nucleus formed by the fusion of a deuteron and a molybdenum nucleus is unstable. It must get rid of excess energy. Therefore, as soon as the merger occurs, a neutron flies out of such a nucleus, and the former nucleus of the molybdenum atom turns into the nucleus of an atom of element No. 43.

b Deuteron - the nucleus of the hydrogen isotope - deuterium. Deuteron used as bombarding particle in charged particle accelerators. The small cross section for neutron capture with the simultaneous efficiency of their moderation (due to the small mass of deuterons, the neutron quickly loses energy upon collision with them) allows the use of deuterons (usually in the form of heavy water, the molecule of which contains two deuterons) to moderate fission neutrons in nuclear reactors.

Natural molybdenum ( Mo, №42) consists of six isotopes, which means, in principle, in an irradiated piece of molybdenum could be atoms of six isotopes of the new element. This is important because some isotopes can be short-lived and therefore chemically elusive, especially since more than a month has passed since the irradiation. But other isotopes of the new element could “survive”. These are what Segre hoped to find.

Let's say that this is where all the pros ended. There were much more “against” ones.

Ignorance of the half-lives of isotopes of element No. 43 worked against the researchers. It could also happen that not a single isotope of element No. 43 exists for more than a month. “Accompanying” nuclear reactions, in which radioactive isotopes of molybdenum, niobium and some other elements were formed, also worked against the researchers. It is very difficult to isolate the minimum amount of an unknown element from a radioactive multicomponent mixture. But this is exactly what Segre and his few assistants had to do.

Work has begun January 30, 1937. First of all, of course, we found out what particles are emitted by molybdenum that has been in a cyclotron and crossed the ocean. He radiated(familiar to us) beta particles- fast nuclear electrons. When about 200 mg of irradiated molybdenum was dissolved in aqua regia, the beta activity of the solution was approximately the same as that of several tens of grams of uranium.

Previously unknown activity was discovered; it remained to determine who it was. "culprit".

First, the radioactive substance was isolated from the solution by chemical means. phosphorus-32, formed from impurities that were in molybdenum. The same solution was then “cross-examined” by row and column of the periodic table. The carriers of unknown activity could be the following isotopes:

• Sh niobium
• Ш zirconium
• Sh Renia
• SH ruthenium
• Finally, molybdenum itself

Only by proving that none of these elements were involved in the emitted electrons could we talk about the discovery of element No. 43...

Two methods were used as the basis for the work:

• Ш one - logical, elimination method
• Ш another - widely used by chemists to separate mixtures "carrier" method, when a compound of this element or another similar to it in chemical properties is “slipped” into a solution that apparently contains one or another element. And if a carrier substance is removed from the mixture, it carries away “related” atoms from there.

First of all ruled out niobium. The solution was evaporated, and the resulting precipitate was again dissolved, this time in potassium hydroxide. Some elements remained in the undissolved part, but unknown activity went into solution. And then they added to it potassium niobate, so that stable niobium “leads away” radioactive. If, of course, it was present in the solution. Niobium is gone, but the activity remains. Same test subjected zirconium. But the zirconium fraction also turned out to be inactive.

Then precipitated molybdenum sulfide, but the activity still remained in solution.

After this, the most difficult thing began: it was necessary to separate unknown activity and rhenium. After all, the impurities contained in the “tooth” material could turn not only into phosphorus-32, but also into radioactive isotopes of rhenium. This seemed all the more likely since it was the rhenium compound that brought the unknown activity out of the solution. And as the Noddacks found out, element No. 43 should be more similar to rhenium than to manganese or any other element. Separating the unknown activity from rhenium meant finding a new element, because all other "candidates" had already been rejected.

Emilio Segre and his closest assistant Carlo Perier were able to do this. They found that in hydrochloric acid solutions (0.4...5 normal), a carrier of unknown activity precipitates when hydrogen sulfide is passed through the solution. But rhenium also falls out at the same time. If precipitation is carried out from a more concentrated solution (10-normal), then rhenium precipitates completely, and the element carrying unknown activity only partially.

Finally, for control purposes, Perrier conducted experiments to separate a carrier of unknown activity from ruthenium and manganese. And then it became clear that beta particles could only be emitted by the nuclei of a new element.

b The new element was named technetium - from the Greek fenzyu, meaning "artificial", referring to the discovery of an element by synthesis.

These experiments were completed in June 1937. So it was the first of the chemical “dinosaurs” was recreated - elements that once existed in nature, but were completely “extinct” as a result of radioactive decay.

Note that we later discovered in the ground some quantities of technetium formed as a result of the spontaneous fission of uranium. The same thing, by the way, happened with neptunium And plutonium: at first item received artificially, and already Then, having studied it, managed to find in nature.

The conclusion to be drawn here is. Above we presented the detailed progress of work on the artificial production by scientists of the long-awaited element No. 43. But now we can sum it up in a nutshell:

• 1) piece of irradiated in a cyclotron molybdenum had strong radioactivity.
• 2) Emilio Segre and Carlo Perrier found that this radioactivity cannot be attributed either to molybdenum itself or to possible impurities of niobium and zirconium in the piece. But when working with rhenium, such radioactivity is observed.