The discovery of tellurium (English Tellurium, German Tellur, French Tellure) refers to the beginning of the flourishing of chemical-analytical research in the second half of the 18th century. By that time, a new gold-bearing ore had been found in Austria in the region of Semigorye (Transylvania). It was then called paradoxical gold (Aurum paradoxicum), white gold (Aurum album), problematic gold (Aurum problematicum), since mineralogists did not know anything about the nature of this ore, but the miners believed that it contained bismuth or antimony. In 1782, Müller (later Baron Reichenstein), a mining inspector in Semigorye, examined the ore and isolated, as he believed, a new metal from it. To verify his discovery, Müller sent a sample of the "metal" to the Swedish analytical chemist Bergman. Bergman, then already seriously ill, began research, but managed to establish only that the new metal differs in chemical properties from antimony. The death of Bergman, which followed soon after, interrupted the research, and more than 16 years passed before they were resumed. In the meantime, in 1786 Kitaibel, a professor of botany and chemistry at the University of Pest, isolated from the mineral wehrlite (containing silver, iron, and bismuth tellurides) some metal that he considered hitherto unknown. Kitaibel compiled a description of the new metal, but did not publish it, but only sent it to some scientists. So it came to the Viennese mineralogist Estner, who introduced him to Klaproth. The latter gave a favorable review of Kitaibel's work, but the existence of the new metal has not yet been conclusively confirmed. Klaproth continued the research of Kitaibel and, as a result, completely eliminated all doubts. In January 1798, he delivered a report to the Berlin Academy of Sciences about his discovery in Transylvanian "white gold" of a special metal (!), which was obtained "from the mother earth" and therefore called tellurium (Tellur) from the word tellus earth (planet). Indeed, the first decades of the XIX century. tellurium was classified as a metal. In 1832 r. Berzelius drew attention to the similarity of tellurium with selenium and sulfur (which had been pointed out before), after which tellurium was ranked among the metalloids (according to the nomenclature of Berzelius). In Russian chemical literature of the early 19th century. the new element was called tellurium, tellurium, tellurium, tellurium; after the appearance of the textbook of chemistry by Hess, the name tellurium took root.

It is unlikely that anyone will believe the story of a sea captain who, in addition, is a professional circus wrestler, a well-known metallurgist and a consulting physician in a surgical clinic. In the world of chemical elements, such a variety of professions is a very common phenomenon, and Kozma Prutkov's expression is inapplicable to them: "A specialist is like a flux: his fullness is one-sided." Let us recall (even before talking about the main object of our story) iron in machines and iron in blood, iron - a magnetic field concentrator and iron - an integral part of ocher ... True, sometimes it took much more time to "professional training" of the elements than to prepare intermediate yoga. So element No. 52, which we are about to tell, was used for many years only to demonstrate what it really is, this element, named after our planet: "tellurium" - from tellus, which in Latin means "Earth ".
This element was discovered almost two centuries ago. In 1782, the mining inspector Franz Josef Müller (later Baron von Reichenstein) examined the gold ore found in Semigorye, on the territory of the then Austria-Hungary. It turned out to be so difficult to decipher the composition of the ore that it was called Aurumaticum - “doubtful gold”. It was from this "gold" that Muller isolated a new metal, but there was no complete certainty that it was really new. (Later it turned out that Müller was wrong about something else: the element he discovered was new, but it can only be classified as a metal with a big stretch.)

To dispel doubts, Müller turned to a prominent specialist, the Swedish mineralogist and analytical chemist Bergman, for help.
Unfortunately, the scientist died before he could finish the analysis of the sent substance - in those years, analytical methods were already quite accurate, but the analysis took a very long time.
Other scientists tried to study the element discovered by Muller, but only 16 years after its discovery, Martin Heinrich Klaproth, one of the greatest chemists of that time, irrefutably proved that this element was actually new, and proposed the name “tellurium” for it.
As always, after the discovery of the element, the search for its applications began. Apparently, proceeding from the old principle, dating back to the times of iatrochemistry - the world is a pharmacy, the Frenchman Fournier tried to treat some serious diseases with tellurium, in particular leprosy. But without success - only many years later Tellurium was able to provide some "small services" to doctors. More precisely, not tellurium itself, but salts of tellurous acid K 2 Te0 3 and Na 2 Te0 3 , which began to be used in microbiology as dyes that impart a certain color to the studied bacteria. So, with the help of tellurium compounds, a diphtheria bacillus is reliably isolated from a mass of bacteria. If not in treatment, then at least in diagnosis, element No. 52 turned out to be useful to doctors.
But sometimes this element, and even more so some of its compounds, add trouble to doctors. Tellurium is quite toxic. In our country, the maximum allowable concentration of tellurium in the air is 0.01 mg/m3. Of the tellurium compounds, the most dangerous is hydrogen telluride H 2 Te, a colorless poisonous gas with an unpleasant odor. The latter is quite natural: tellurium is an analogue of sulfur, which means that H 2 Te should be similar to hydrogen sulfide. It irritates the bronchi, adversely affects the nervous system.
These unpleasant properties did not prevent tellurium from entering technology and acquiring many "professions".
Metallurgists are interested in tellurium because even small additions to lead greatly increase the strength and chemical resistance of this important metal. Lead doped with tellurium is used in the cable and chemical industries. Thus, the service life of sulfuric acid production apparatuses coated on the inside with a lead-tellurium alloy (up to 0.5% Te) is twice as long as that of similar apparatuses lined with lead alone. The addition of tellurium to copper and steel facilitates their machining.

In the glass industry, tellurium is used to give the glass a brown color and a higher refractive index. In the rubber industry, as an analogue of sulfur, it is sometimes used to vulcanize rubbers.

Tellurium - semiconductor

However, these industries were not responsible for the jump in prices and demand for element No. 52. This jump took place in the early 60s of our century. Tellurium is a typical semiconductor, and a technological semiconductor. Unlike germanium and silicon, it is relatively easy to melt (melting point 449.8 ° C) and evaporate (boils at a temperature just below 1000 ° C). From it, therefore, it is easy to obtain thin semiconductor films, which are of particular interest to modern microelectronics.
However, pure tellurium as a semiconductor is used to a limited extent - for the manufacture of field-effect transistors of some types and in devices that measure the intensity of gamma radiation. Moreover, an impurity of tellurium is deliberately introduced into gallium arsenide (the third most important semiconductor after silicon and germanium) in order to create electronic type conductivity in it.
The scope of some tellurides, compounds of tellurium with metals, is much wider. Bismuth Bi 2 Te 3 and antimony Sb 2 Te 3 tellurides have become the most important materials for thermoelectric generators. To explain why this happened, let's make a small digression into the field of physics and history.
A century and a half ago (in 1821), the German physicist Seebeck discovered that in a closed electrical circuit consisting of different materials, the contacts between which are at different temperatures, an electromotive force is created (it is called thermo-EMF). After 12 years, the Swiss Peltier discovered an effect opposite to the Seebeck effect: when an electric current flows through a circuit made up of different materials, at the points of contact, in addition to the usual Joule heat, a certain amount of heat is released or absorbed (depending on the direction of the current).

For about 100 years, these discoveries remained a "thing in itself", curious facts, nothing more. And it would not be an exaggeration to say that a new life for both of these effects began after Academician A.F. Ioffe and his co-workers developed the theory of the use of semiconductor materials for the manufacture of thermoelements. And soon this theory was embodied in real thermoelectric generators and thermoelectric refrigerators for various purposes.
In particular, thermoelectric generators, in which bismuth, lead and antimony tellurides are used, provide energy to artificial satellites of the Earth, navigation and meteorological installations, cathodic protection devices for main pipelines. The same materials help maintain the desired temperature in many electronic and microelectronic devices.
In recent years, another chemical compound of tellurium with semiconductor properties, cadmium telluride CdTe, has attracted great interest. This material is used for the manufacture of solar cells, lasers, photoresistors, counters of radioactive radiation. Cadmium telluride is also famous for being one of the few semiconductors in which the Hahn effect is noticeably manifested.
The essence of the latter lies in the fact that the very introduction of a small plate of the corresponding semiconductor into a sufficiently strong electric field leads to the generation of high-frequency radio emission. The Hahn effect has already found application in radar technology.
In conclusion, we can say that quantitatively the main "profession" of tellurium is the alloying of lead and other metals. Qualitatively, the main thing, of course, is the work of tellurium and tellurides as semiconductors.

Useful admixture

In the periodic table, the place of tellurium is in the main subgroup of group VI, next to sulfur and selenium. These three elements are similar in chemical properties and often accompany each other in nature. But the proportion of sulfur in the earth's crust is 0.03%, selenium is only 10-5%, and tellurium is even an order of magnitude smaller - 10~6%. Naturally, tellurium, like selenium, is most often found in natural sulfur compounds - as an impurity. It happens, however (remember the mineral in which tellurium was discovered), that it is in contact with gold, silver, copper and other elements. More than 110 deposits of forty tellurium minerals have been discovered on our planet. But it is always mined at the same time either with selenium, or with gold, or with other metals.
In Russia, copper-nickel tellurium-bearing ores of Pechenga and Monchegorsk, tellurium-bearing lead-zinc ores of Altai and a number of other deposits are known.

Tellurium is isolated from copper ore at the stage of purification of blister copper by electrolysis. A precipitate falls to the bottom of the electrolyzer - sludge. This is a very expensive semi-finished product. For illustration, the composition of the sludge from one of the Canadian plants is given: 49.8% copper, 1.976% gold, 10.52% silver, 28.42% selenium and 3.83% tellurium. All these valuable components of the sludge must be separated, and there are several ways to do this. Here is one of them.
The sludge is melted in a furnace and air is passed through the melt. Metals, except for gold and silver, oxidize, turn into slag. Selenium and tellurium are also oxidized, but into volatile oxides, which are captured in special apparatuses (scrubbers), then dissolved and converted into acids - selenous H 2 SeOz and tellurous H 2 TeOz. If sulfur dioxide gas S0 2 is passed through this solution, reactions will occur
H 2 Se0 3 + 2S0 2 + H 2 0 → Se ↓ + 2H 2 S0 4 .
H2Te03 + 2S02 + H20 → Te ↓ + 2H 2 S0 4 .
Tellurium and selenium fall out at the same time, which is very undesirable - we need them separately. Therefore, the process conditions are selected in such a way that, in accordance with the laws of chemical thermodynamics, primarily selenium is reduced first. This is helped by the selection of the optimal concentration of hydrochloric acid added to the solution.
Then tellurium is precipitated. The precipitated gray powder, of course, contains a certain amount of selenium and, in addition, sulfur, lead, copper, sodium, silicon, aluminum, iron, tin, antimony, bismuth, silver, magnesium, gold, arsenic, chlorine. Tellurium has to be purified from all these elements first by chemical methods, then by distillation or zone melting. Naturally, tellurium is extracted from different ores in different ways.

Tellurium is harmful

Tellurium is used more and more widely and, therefore, the number of people working with it is increasing. In the first part of the story about element No. 52, we already mentioned the toxicity of tellurium and its compounds. Let's talk about this in more detail - precisely because more and more people have to work with tellurium. Here is a quote from a dissertation on tellurium as an industrial poison: white rats injected with an aerosol of tellurium "became restless, sneezed, rubbed their faces, became lethargic and sleepy." Tellurium acts in a similar way on people.

And myself tellurium and its compounds can bring misfortunes of different "calibers". For example, they cause baldness, affect the composition of the blood, and can block various enzyme systems. Symptoms of chronic poisoning with elemental tellurium - nausea, drowsiness, emaciation; exhaled air acquires a nasty garlic smell of alkyl tellurides.
In acute tellurium poisoning, serum with glucose is administered intravenously. and sometimes even morphine. As a prophylactic, ascorbic acid is used. But the main prevention is reliable sealing of apparatuses, automation of processes in which tellurium and its compounds are involved.

Element number 52 brings many benefits and therefore deserves attention. But working with him requires caution, clarity and, again, focused attention.
TELLURIUM APPEARANCE. Crystalline tellurium is most similar to antimony. Its color is silvery white. Crystals are hexagonal, the atoms in them form helical chains and are connected by covalent bonds with their nearest neighbors. Therefore, elemental tellurium can be considered an inorganic polymer. Crystalline tellurium is characterized by a metallic luster, although in terms of the complex of chemical properties it can rather be attributed to non-metals. Tellurium is brittle and fairly easy to powder. The question of the existence of an amorphous modification of tellurium has not been unambiguously resolved. When tellurium is reduced from telluric or telluric acids, a precipitate precipitates, but it is still not clear whether these particles are truly amorphous or just very small crystals.
BICOLOR ANHYDRIDE. As it should be for the analogue of sulfur, tellurium exhibits valencies 2-, 4+ and 6+ and much less often 2+. Tellurium monoxide TeO can exist only in gaseous form and is easily oxidized to Te0 2 . It is a white non-hygroscopic, quite stable crystalline substance, melting without decomposition at 733°C; it has a polymer structure.
Tellurium dioxide almost does not dissolve in water - only one part of Te0 2 per 1.5 million parts of water passes into the solution and a solution of weak tellurous acid H 2 Te0 3 of negligible concentration is formed. The acidic properties of telluric acid are also weakly expressed.

H 6 TeO 6 . This formula (and not H 2 TeO 4) was assigned to it after salts of the composition Ag 6 Te0 6 and Hg 3 Te0 6 were obtained, which dissolve well in water. TeOz anhydride, which forms telluric acid, practically does not dissolve in water. This substance exists in two modifications - yellow and gray: α-TeOz and β-TeOz. Gray telluric anhydride is very stable: even when heated, it is not affected by "acids and concentrated alkalis. It is purified from the yellow variety by boiling the mixture in concentrated caustic potash.

SECOND EXCEPTION. When creating the periodic table, Mendeleev placed tellurium and its neighboring iodine (as well as argon and potassium) in groups VI and VII not in accordance with, but in spite of their atomic weights. Indeed, the atomic mass of tellurium is 127.61, and that of iodine is 126.91. This means that iodine would have to stand not behind tellurium, but ahead of it. Mendeleev, however, did not doubt the right
the correctness of his reasoning, since he believed that the atomic weights of these elements were not determined accurately enough. A close friend of Mendeleev, the Czech chemist Boguslav Brauner carefully checked the atomic weights of tellurium and iodine, but his data coincided with the previous ones. The legitimacy of exceptions confirming the rule was established only when the basis of the periodic system was not atomic weights, but nuclear charges, when the isotopic composition of both elements became known. Tellurium, unlike iodine, is dominated by heavy isotopes.
By the way, about isotons. Now 22 isotopes of element No. 52 are known. Eight of them - with mass numbers 120, 122, 123, 124, 125, 126, 128 and 130 - are stable. The last two isotopes are the most common: 31.79 and 34.48%, respectively.

TELLURIUM MINERALS. Although there is significantly less tellurium on Earth than selenium, more minerals of element #52 are known than those of its counterpart. According to their composition, tellurium minerals are twofold: either tellurides, or telluride oxidation products in the earth's crust. Calaverite AuTe 2 and krennerite (Au, Ag) Te2, which are among the few natural gold compounds, are among the first. Natural tellurides of bismuth, lead, and mercury are also known. Native tellurium is very rare in nature. Even before the discovery of this element, it was sometimes found in sulfide ores, but could not be correctly identified. Tellurium minerals have no practical value - all industrial tellurium is a by-product of processing ores of other metals.

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Presentation on the topic: Tellurium

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Tellurium Tellurium (lat. Tellurium) is a chemical element with atomic number No. 52 in the periodic system and an atomic weight of 127.60; denoted by the symbol Te, belongs to the family of metalloids. It occurs in nature in the form of eight stable isotopes with mass numbers 120, 122-126, 128, 130, of which 128Te and 130Te are the most common. Of the artificially obtained radioactive isotopes, 127Te and 129Te are widely used as labeled atoms.

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From history... It was first found in 1782 in the gold ores of Transylvania by mining inspector Franz Josef Müller (later Baron von Reichenstein), on the territory of Austria-Hungary. In 1798, Martin Heinrich Klaproth isolated tellurium and determined its most important properties. The first systematic studies of the chemistry of tellurium were carried out in the 1930s. 19th century I. Ya. Berzelius.

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"Aurum paradoxum" - paradoxical gold, so called tellurium, after at the end of the 18th century it was discovered by Reichenstein in combination with silver and yellow metal in the mineral sylvanite. The fact that gold, which is usually always found in its native state, was discovered in conjunction with tellurium seemed an unexpected phenomenon. That is why, having attributed properties similar to the yellow metal, it was called the yellow metal paradoxical.

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The discovery of tellurium refers to the beginning of the flourishing of chemical-analytical research in the second half of the 18th century. By that time, a new gold-bearing ore had been found in Austria in the region of Semigorye (Transylvania). It was then called paradoxical gold, white gold, problematic gold, since mineralogists did not know anything about the nature of this ore, while the miners believed that it contained bismuth or antimony

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In 1782, Müller examined the ore and isolated from it, as he believed, a new metal. To verify his discovery, Müller sent a sample of the "metal" to the Swedish analytical chemist Bergman. Bergman, then already seriously ill, began research, but managed to establish only that the new metal differs in chemical properties from antimony. The death of Bergman, which followed soon after, interrupted the research, and more than 16 years passed before they were resumed. In the meantime, in 1786 Kitaibel, a professor of botany and chemistry at the University of Pest, isolated from the mineral wehrlite (containing silver, iron, and bismuth tellurides) some metal that he considered hitherto unknown. Kitaibel compiled a description of the new metal, but did not publish it, but only sent it to some scientists. So it came to the Viennese mineralogist Estner, who introduced him to Klaproth. The latter gave a favorable review of Kitaibel's work, but the existence of the new metal has not yet been conclusively confirmed. Klaproth continued the research of Kitaibel and, as a result, completely eliminated all doubts. In January 1798, he made a report to the Berlin Academy of Sciences about his discovery in the Transylvanian "white yellow metal" of a special metal, which was obtained "from mother earth." Indeed, the first decades of the XIX century. tellurium was classified as a metal. In 1832 r. Berzelius drew attention to the similarity of tellurium with selenium and sulfur (which had been pointed out earlier), after which tellurium was classified as a metalloid (according to the nomenclature of Berzelius)

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The origin of the name Later (1798), when M. Klaproth studied the new substance in more detail, he named it tellurium in honor of the Earth, the bearer of chemical "miracles" (from the Latin word "tellus" - earth). This name has come into use by chemists of all countries.

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Finding in nature Content in the earth's crust 1·10-6% by weight. Metal tellurium can only be found in the laboratory, but its compounds can be found around us much more often than it might seem. About 100 tellurium minerals are known. The most important of them are altaite PbTe, sylvanite AgAuTe4, calaverite AuTe2, tetradymite Bi2Te2S, krennsrite AuTe2, petzite AgAuTe2. There are oxygen compounds of tellurium, for example TeO2 - tellurium ocher. Native tellurium is also found together with selenium and sulfur (Japanese telluric sulfur contains 0.17% Te and 0.06% Se).

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Peltier module Many people are familiar with Peltier thermoelectric modules, which are used in portable refrigerators, thermoelectric generators and sometimes for extreme cooling of computers. The main semiconductor material in such modules is bismuth telluride. At present, it is the most popular semiconductor material. If you look at the thermoelectric module from the side, you can see rows of small "cubes".

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Physical properties Tellurium is silvery-white in color with a metallic luster, brittle, becomes plastic when heated. Crystallizes in the hexagonal system. Tellurium is a semiconductor. Under normal conditions and up to the melting point, pure Tellurium has a p-type conductivity. With a decrease in temperature in the range (-100 ° C) - (-80 ° C), a transition occurs: the conductivity of Tellurium becomes n-type. The temperature of this transition depends on the purity of the sample, and it is lower, the purer the sample. Density = 6.24 g/cm³ Melting point = 450°C Boiling point = 990°C Heat of fusion = 17.91 kJ/mol Heat of vaporization = 49.8 kJ/mol Molar heat capacity = 25.8 J/(K mol ) Molar volume = 20.5 cm³/mol

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Chemical properties Tellurium is a non-metal. In compounds, tellurium exhibits oxidation states: -2, +4, +6 (valency II, IV, VI). Tellurium is chemically less active than sulfur and oxygen. Tellurium is stable in air, but burns at high temperatures to form TeO2. Te interacts with halogens in the cold. When heated, it reacts with many metals, giving tellurides. Let's dissolve in alkalis. Under the action of nitric acid, Te is converted into telluric acid, and under the action of aqua regia or 30% hydrogen peroxide, it is converted into telluric acid.

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Physiological action When heated, Tellurium reacts with hydrogen to form hydrogen telluride - H2Te, a colorless poisonous gas with a sharp, unpleasant odor. Tellurium and its volatile compounds are toxic. Ingestion causes nausea, bronchitis, pneumonia. The maximum allowable concentration in the air varies for various compounds 0.007-0.01 mg / m³, in water 0.001-0.01 mg / l.

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Obtaining The main source is sludge from the electrolytic refining of copper and lead. The sludge is roasted, the tellurium remains in the cinder, which is washed with hydrochloric acid. Tellurium is isolated from the resulting hydrochloric acid solution by passing sulfur dioxide SO2 through it. Sulfuric acid is added to separate selenium and tellurium. In this case, tellurium dioxide TeO2 precipitates, while H2SeO3 remains in solution. Tellurium is reduced from TeO2 oxide with coal. To purify tellurium from sulfur and selenium, its ability, under the action of a reducing agent (Al) in an alkaline medium, to pass into soluble disodium ditelluride Na2Te2: 6Te + 2Al + 8NaOH = 3Na2Te2 + 2Na is used. To precipitate tellurium, air or oxygen is passed through the solution: 2Na2Te2 + 2H2O + O2 = 4Te + 4NaOH. To obtain high purity tellurium, it is chlorinated with Te + 2Cl2 = TeCl4. The resulting tetrachloride is purified by distillation or rectification. Then the tetrachloride is hydrolyzed with water: TeCl4 + 2H2O = TeO2 + 4HCl, and the resulting TeO2 is reduced with hydrogen: TeO2 + 4H2 = Te + 2H2O.

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Etymology of the names of chemical elements.

The science of etymology deals with the origin of a word and the description of its relationship with other words of the same language or other languages. In other words, etymology is a branch of linguistics that studies the origin of words in different languages. So guys today in the lesson we will look at the origin of some chemical elements. We just don't have enough time for everything. The following groups of elements can be distinguished.

Elements named after celestial bodies or planets in the solar system.

Uranus, Neptunium, Plutonium

In 1781, the English astronomer William Herschel discovered a new planet, which was named Uranus - after the ancient Greek sky god Uranus, the grandfather of Zeus. In 1789, M. Klaproth isolated a black heavy substance from the pitchblende mineral, which he mistook for metal and, according to the tradition of alchemists, “tied” its name to the recently discovered planet. And he renamed the resin blende into uranium pitch (it was with her that the Curies worked).

In 1846, astronomers discovered a new planet predicted shortly before by the French astronomer Le Verrier. She was named Neptune - after the ancient Greek god of the underwater kingdom. When, in 1850, a new metal was discovered in a mineral brought to Europe from the United States, it was suggested to call it neptunium, under the impression of the discovery of astronomers.

In 1930, the ninth planet of the solar system was discovered, predicted by the American astronomer Lovell. She was named Pluto - after the ancient Greek god of the underworld. Therefore, it was logical to call the next element after neptunium plutonium; it was obtained in 1940 as a result of the bombardment of uranium with deuterium nuclei.

Cerium

On New Year's Eve, January 1, 1801, Italian astronomer Giuseppe Piazzi discovered the first minor planet, which was soon "christened" Ceres. And just two years later, in 1803, a new element was discovered, named after the asteroid Ceres, cerium.

Elements named after mythical heroes

Cadmium

It was discovered in 1818 by the German chemist and pharmacist Friedrich Stromeyer in zinc carbonate, from which medicines were obtained at a pharmaceutical factory. Since ancient times, the Greek word "cadmeia" has been used to refer to carbonate zinc ores. The name goes back to the mythical Cadmus (Kadmos) - the hero of Greek mythology, the brother of Europe, the king of the Cadmean land, the founder of Thebes, the winner of the dragon, from whose teeth warriors grew.

Niobium and tantalum

In 1801, the English chemist Charles Hatchet analyzed a black mineral stored in the British Museum and found back in 1635 in what is now Massachusetts, USA. Hatchet discovered an oxide of an unknown element in the mineral, which was named Columbia - in honor of the country where it was found (at that time the United States did not yet have a well-established name, and many called it Columbia after the discoverer of the continent). The mineral was called columbite. In 1802, the Swedish chemist Anders Ekeberg isolated another oxide from columbite, which stubbornly refused to dissolve (as they said then, to be saturated) in any acid. The "legislator" in the chemistry of those times, the Swedish chemist Jene Jakob Berzelius, proposed that the metal contained in this oxide be called tantalum.

Promethium

In 1947, the American researchers J. Marinsky, L. Glendenin and C. Coryell, chromatographically separated the fission products of uranium in a nuclear reactor. Coriella's wife suggested that the discovered element be named promethium, after Prometheus, who stole fire from the gods and gave it to people. This emphasized the formidable power contained in the nuclear “fire”. The researcher's wife was right

Thorium

In 1828 Y.Ya. Berzelius discovered in a rare mineral sent to him from Norway, a compound of a new element, which he named thorium - in honor of the Old Norse god Thor.

Vanadium

Discovered in 1830 by the Swedish chemist Nils Sefström in blast furnace slag. Named after the Norse goddess of beauty Vanadis, or Vanadis. In this case, it also turned out that vanadium had been discovered before, and even more than once - the Mexican mineralogist Andree Manuel del Rio in 1801 and the German chemist Friedrich Wöhler shortly before the discovery of Sefstrom. But del Rio himself abandoned his discovery, deciding that he was dealing with chromium, and Wöhler was prevented from completing his work by illness.

Helium

On November 13, 1968, the Italian astronomer Angelo Secchi drew attention to a "remarkable line" in the solar spectrum near the well-known yellow D line of sodium. He suggested that this line is emitted by hydrogen under extreme conditions. It was not until January 1871 that Lockyer suggested that this line might belong to a new element. For the first time the word "helium" was uttered in his speech by the President of the British Association for the Advancement of Sciences, William Thomson, in July of the same year. The name was given by the name of the ancient Greek sun god Helios. In 1895, the English chemist William Ramsay collected an unknown gas isolated from the uranium mineral cleveite during its treatment with acid and, using Lockyer, investigated it by the spectral method. As a result, a "solar" element was also discovered on Earth.

Elements named after states and geographical features

Ruthenium

This metal of the platinum group was discovered by K. K. Klaus in Kazan in 1844 during his analysis of the so-called factory platinum deposits. Klaus isolated the new metal as a sulfide and suggested that it be named ruthenium after Russia.

Germanium- in honor of Germany

Gallium, Francium- in honor of France

Scandium- in honor of the Scandinavian Peninsula

Europium- in honor of Europe

Americium- in honor of America

Polonium- in honor of Poland

Elements named after cities

Hafnium- in honor of Copenhagen

Lutetium- in honor of Paris (Lutetia)

Berkelium- after a city in the USA

Dubnium- in honor of the city of Dubna in Russia

Yttrium, Terbium, Erbium, Ytterbium- in honor of the city of Ytterby in Sweden, where a mineral containing these elements was discovered

Holmium- in honor of Stockholm (its old Latin name is Holmia)

Elements named after explorers

Gadolinium

In 1794, the Finnish chemist and mineralogist Johan Gadolin discovered an oxide of an unknown metal in a mineral found near Ytterby. In 1879, Lecoq de Boisbaudran called this oxide gadolinium earth (Gadolinia), and when the metal was isolated from it in 1896, it was named gadolinium. This was the first time that a chemical element was named after a scientist.

Fermium and Einsteinium

In 1953, isotopes of two new elements were discovered in the products of a thermonuclear explosion that the Americans produced in 1952, which they named fermium and einsteinium - in honor of the physicists Enrico Fermi and Albert Einstein.

Curium

The element was obtained in 1944 by a group of American physicists led by Glenn Seaborg by bombarding plutonium with helium nuclei. It was named after Pierre and Marie Curie.

Mendelevium

It was first announced in 1955 by the Seaborg group, but it was not until 1958 that reliable data were obtained at Berkeley. Named after D.I. Mendeleev.

Nobelium

For the first time, its receipt was reported in 1957 by an international group of scientists working in Stockholm, which proposed to name the element in honor of Alfred Nobel. Later, the results were found to be inaccurate. The first reliable data on element 102 were obtained by the group of G.N. Flerova in 1966. Scientists proposed to rename the element in honor of the French physicist Frederic Joliot-Curie and call it Joliotium (Jl). As a compromise, there was also a proposal to name the element florovium - in honor of Flerov. The question remained open, and for several decades the Nobel symbol was placed in brackets. So it was, for example, in the 3rd volume of the Chemical Encyclopedia, published in 1992, which contained an article on nobelium. However, over time, the issue was resolved, and starting from the 4th volume of this encyclopedia (1995), as well as in other editions, the Nobel symbol was freed from brackets.

Laurence

The production of various isotopes of element 103 was reported in 1961 and 1971 (Berkeley), in 1965, 1967 and 1970 (Dubna). The element was named after Ernest Orlando Lawrence, an American physicist who invented the cyclotron. Lawrence is named after the Berkeley National Laboratory.

Rutherfordium

The first experiments to obtain element 104 were undertaken by Ivo Zvara and his collaborators back in the 60s. G.N. Flerov and his collaborators reported on the production of another isotope of this element. It was proposed to call it kurchatovium (symbol Ku) - in honor of the head of the atomic project I.V. Kurchatov. American researchers who synthesized this element in 1969 used a new identification technique, believing that the results obtained earlier could not be considered reliable. They proposed the name rutherfordium - in honor of the outstanding English physicist Ernest Rutherford, IUPAC proposed the name dubnium for this element. The International Commission concluded that the honor of discovery should be shared by both groups.

Kurchatovy

According to Seaborg's theory on the similarity of the structure of the electron shells of lanthanides and transuranium elements, element 104, being an analogue of hafnium, should not belong to the group of actionoids, but to the subgroup of titanium, zirconium and hafnium. It was named kurchatovium in honor of the largest Soviet scientist in the field of nuclear physics I. V. Kurchatov.

Bory

The first reliable information about the properties of element 107 was obtained in Germany in the 1980s. The element is named after Niels Bohr.

Homework: §4, answers to questions No. 1, 2,3 to §4.

Element No. 52 was used for many years only to demonstrate what it really is, this element named after our planet: "tellurium" - from tellus, which in Latin means "Earth".This element was discovered almost two centuries ago. In 1782, the mining inspector Franz Josef Müller (later Baron von Reichenstein) examined the gold ore found in Semigorye, on the territory of the then Austria-Hungary. It turned out to be so difficult to decipher the composition of the ore that it was called Aurumaticum - “doubtful gold”. It was from this "gold" that Muller isolated a new metal, but there was no complete certainty that it was really new.

(Later it turned out that Müller was wrong about something else: the element he discovered was new, but it can only be classified as a metal with a big stretch.) To dispel doubts, Müller turned to Bergman, a prominent specialist, a Swedish mineralogist and analytical chemist, for help. unfortunately, the scientist died before he could finish the analysis of what he sent - in those years, analytical methods were already quite accurate, but the analysis took a very long time. They tried to study the element discovered by Muller andotherscientists, but only 16 years after its discoveryMartin Heinrich Klaproth - one of the greatest chemists of that time - irrefutably proved that this element is actually new, and proposed the name "tellurium" for it.

How Andalways, after the discovery of the element, the search for its applications began. Apparently, proceeding from the old principle, dating back to the times of iatrochemistry - the world is a pharmacy, the Frenchman Fournier tried to treat some serious diseases with tellurium, in particular leprosy. But without success - only many years later he was able to provide doctors with some "small services". More precisely, not itself, but salts of telluric acid K 2 TeO 3 andNa 2 TeO 3 ,which began to be used in microbiology as dyes that give a certain color to the studied bacteria. So, with the help of tellurium compounds, a diphtheria bacillus is reliably isolated from a mass of bacteria. If not in treatment, then at least in diagnosis, element No. 52 turned out to be useful to doctors.

But sometimes this element, and even more so some of its compounds, add trouble to doctors. quite toxic. In our country, the maximum allowable concentration of tellurium in the air is 0.01 mg / m 3. Of the tellurium compounds, the most dangerous is hydrogen telluride H 2 Te, a colorless poisonous gas with an unpleasant odor. The latter is quite natural: tellurium is an analogue of sulfur, which means.H2Te should be similar to hydrogen sulfide. He is annoying reaps bronchi,harmful effect on the nervous system.These unpleasant properties did not prevent tellurium from entering technology and acquiring many "professions".Metallurgists are interested in tellurium because even small additions to lead greatly increase the strength and chemical resistance of this important metal. , doped with tellurium, is used in the cable and chemical industries.

Thus, the service life of apparatuses for sulfuric acid production, coated from the inside with a lead-tellurium alloy (up to 0.5% Te), is twice as long as that of similar apparatuses lined with lead alone. The additive of tellurium to copper and steel facilitates their machining. In glass production, tellurium is used to give the glass a brown color and a higher refractive index. In the rubber industry, as an analogue of sulfur, it is sometimes used to vulcanize rubbers.

Article on Tellurium history