Which element is named after the planet earth. Heavenly names of chemical elements. Structure of the Periodic Table

Tellurium – chemical element belonging to the 16th group, located in the periodic table, atomic number 52 and designated by the Latin Te - special identification. The element belongs to the metalloids. Tellurium formula — 4d10 5s2 5p4.

Tellurium - element having a white-silver tint and a metallic luster and fragile structure. At high temperatures, like many metals, tellurium becomes ductile.

Origin of tellurium

The element was discovered in gold mines in the mountains of Transylvania. Humanity knows at least one hundred minerals containing tellurium. In particular, these are silver, gold, copper and zinc. There are various tellurium compounds, for example, these are some types of ocher. In its pure form, in one deposit you can find selenium, tellurium and sulfur, which indicates the possibility of the element being native.

All of the minerals mentioned are more often found in the same deposit with silver, lead and bismuth. In industrial settings, for the most part tellurium is isolated chemically from other metals, despite the fact that its main minerals are quite common. In particular, it is contained in sufficient quantities in chalcopyrite, which is part of nickel-copper and copper pyrite ores.

Additionally, it can be found in, molybdenite and galena, it is also found in copper ores, polymetallic deposits and lead-zinc deposits. These minerals also contain sulfide and antimony rocks containing cobalt and mercury.

Mostly in industry, tellurium is extracted from sludge, which is formed by the electrolytic refining of copper and lead. During processing, the sludge is burned, and the burnt residues contain a certain tellurium content. To isolate the required element, the cinders are washed with hydrochloric acid.

To separate the metal from the resulting acid solution, sulfur dioxide must be passed through it. Obtained in this way tellurium oxide, is processed with coal to obtain a pure element from it. For its further purification, a chlorination procedure is used.

This produces tetrachloride, which must be purified by distillation or rectification. Next, it is hydrolyzed, and the resulting tellurium hydroxide is reduced by hydrogen.

Applications of tellurium

This metal is used in the manufacture of many different materials (copper, lead, iron), so the metallurgy industry is its main consumer. Tellurium makes stainless steel and copper more workable. Also, adding this element to malleable cast iron gives it the positive properties of gray cast iron.

Its casting qualities and machinability are improved. It is able to significantly improve the physical properties of lead, reducing negative corrosion from sulfuric acid during its processing.

Tellurium is widely used in semiconductor devices and electronics. In particular, it is used to produce solar cells. The use of tellurium opens up broad prospects in the application of these advanced technologies. The percentage of production of such equipment has increased significantly in recent years. This led to a noticeable increase in the turnover of tellurium on the world market.

The metal is used, including in space technological developments, in particular, these are alloys with the addition of tellurium, which have unique properties. They are used in technologies for detecting radiation left by spacecraft.

For this reason, the expensive alloy is largely in demand in the military industry, for tracking the enemy in outer space. In addition to this mixture selenium – tellurium is part of the delay powder in detonator caps for explosive devices produced by military factories.

Various tellurium compounds are used in the production of semiconductor compounds with a multilayer structure. Many compounds that include tellurium exhibit remarkable superconductivity.

Tellurium also works for the benefit of ordinary people. In particular, metal oxide is used in the production of compact discs to create a rewritable thin layer on them. It is also present in some microcircuits, for example, those produced by Intel. Bismuth telluride is included in many thermoelectric devices and infrared sensors.

This metal is also used when painting ceramic products. In the manufacture of fiberglass for information communications (television, Internet, etc.), the participation of tellurium in cable production is based on the positive property of tellurides and selenides to increase optical refraction when added to glass.

Vulcanization of rubber also involves the use of substances close to metal - selenium or sulfur, which can be replaced, if possible, by tellurium. Rubber with its addition will demonstrate much better qualities. Tellurium has also found its niche in medicine - it is used in the diagnosis of diphtheria.

Tellurium price

In terms of consumption of this rare earth metal in the world, China is in first place, Russia is in second, and the USA is in third. Total consumption is 400 tons of metal per year. Tellurium is usually sold in the form of powder, rods or.

Due to the small volumes of production, due to its relatively small content in rocks, the price of tellurium is quite high. Approximately, if you do not take into account the constant price hikes for tellurium, buy It can be sold on the world market for $200-300 per kilogram of metal. The price also depends on the degree of purification of the metal from unwanted impurities.

But, despite the inaccessibility of this unique element, there is always considerable demand for it, with constant growth trends. Every year the range of areas requiring the use of tellurium and its compounds is expanding.

It is easy to follow the trend of rising prices for tellurium by comparing prices at the beginning of 2000, when it was $30 per 1 kg, and ten years later, when it reached $350. And despite the fact that a year later it still fell, there is a serious tendency for prices to rise, due to a fall in tellurium production volumes.

The fact is that the tellurium market directly depends on the volume of production, since tellurium is one of the by-products during its extraction. At the moment, the copper market has significantly reduced its turnover, and new technologies for its production have appeared, the features of which will significantly affect the volume of additional tellurium produced.

This will certainly affect its supplies, and naturally prices. According to estimates, a new price hike is expected in a couple of years. Despite the fact that tellurium has certain analogues in industry, they do not have such valuable properties.

This situation on the world market is not at all beneficial for many manufacturers whose production involves tellurium. In particular, these are manufacturers of solar panels, whose products have been gaining increasing popularity in recent years.

It is unlikely that anyone will believe the story about the sea captain, who, in addition, is a professional circus wrestler, a famous metallurgist and a consultant physician at a surgical clinic. In the world of chemical elements, such a variety of professions is a very common phenomenon, and Kozma Prutkov’s expression does not apply to them: “A specialist is like gumboil: his completeness is one-sided.” Let us remember (even before talking about the main object of our story) iron in cars and iron in blood, iron is a magnetic field concentrator and iron is an integral part of ocher... True, the “professional training” of elements sometimes took much more time than preparation intermediate yoga. So element No. 52, which we are about to talk about, 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, mining inspector Franz Joseph Müller (later Baron von Reichenstein) examined gold ore found in Semigorye, in what was then Austria-Hungary. It turned out to be so difficult to decipher the composition of the ore that it was called Aurum problematicum - “doubtful gold.” It was from this “gold” that Muller isolated a new metal, but there was no complete confidence that it was truly new. (It later 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 great reserve.)

To dispel doubts, Müller turned for help to a prominent specialist, the Swedish mineralogist and analytical chemist Bergman.
Unfortunately, the scientist died before finishing the analysis of the sent substance - in those years, analytical methods were already quite accurate, but the analysis took a lot of time.
Other scientists also tried to study the element discovered by Müller, but only 16 years after its discovery, Martin Heinrich Klaproth, one of the leading chemists of that time, irrefutably proved that this element was in fact new and proposed the name “tellurium” for it.
As always, after the discovery of the element, the search for its applications began. Apparently, based on the old principle dating back to the times of atrochemistry - 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 was tellurium able to provide doctors with some “minor services”. More precisely, not tellurium itself, but salts of telluric acid K 2 Te0 3 and Na 2 Te0 3, which began to be used in microbiology as dyes that give a certain color to the bacteria being studied. Thus, with the help of tellurium compounds, the 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 permissible 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 and has a 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. Lead doped with tellurium is used in the cable and chemical industries. Thus, the service life of sulfuric acid production devices coated on the inside with a lead-tellurium alloy (up to 0.5% Te) is twice as long as that of the same devices lined simply with lead. The addition of tellurium to copper and steel facilitates their machining.

Tellurium - semiconductor

However, these industries were not responsible for the jump in prices and demand for element No. 52. This jump occurred in the early 60s of our century. Tellurium is a typical semiconductor, and a technological semiconductor. Unlike germanium and silicon, it melts relatively easily (melting point 449.8 ° C) and evaporates (boils at a temperature just below 1000 ° C). Consequently, it is easy to obtain thin semiconductor films from it, 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, a tellurium impurity 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 application of some tellurides - compounds of tellurium with metals - is much broader. Tellurides of bismuth Bi 2 Te 3 and antimony Sb 2 Te 3 have become the most important materials for thermoelectric generators. To explain why this happened, let's take a short 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 composed of different materials, at the contact points, in addition to the usual Joule heat, a certain amount of heat is released or absorbed (depending on the direction of the current).

For approximately 100 years, these discoveries remained “things in themselves”, 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 colleagues developed the theory of using 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, which use tellurides of bismuth, lead and antimony, provide energy to artificial Earth satellites, navigation and meteorological installations, and cathodic protection devices for main pipelines. The same materials help maintain the desired temperature in many electronic and microelectronic devices.
In recent years, another tellurium chemical compound with semiconductor properties, cadmium telluride CdTe, has attracted great interest. This material is used for the manufacture of solar cells, lasers, photoresistors, and radioactive radiation counters. Cadmium telluride is also famous for the fact that it is one of the few semiconductors in which the Han effect is noticeably manifested.
The essence of the latter is 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 alloying 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, tellurium is located 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 share of sulfur in the earth's crust is 0.03%, selenium is only 10-5%, tellurium is even an order of magnitude less - 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 comes into 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 together with either selenium, or gold, or other metals.
In Russia, copper-nickel tellurium-containing ores of Pechenga and Monchegorsk, tellurium-containing lead-zinc ores of Altai and a number of other deposits are known.

Tellurium is isolated from copper ore at the stage of purifying blister copper by electrolysis. A sediment - sludge - falls to the bottom of the electrolyser. This is a very expensive intermediate product. To illustrate the composition of the sludge from one of the Canadian plants: 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's one of them.
The sludge is melted in a furnace and air is passed through the melt. Metals, except gold and silver, oxidize and turn into slag. Selenium and tellurium are also oxidized, but into volatile oxides, which are captured in special devices (scrubbers), then dissolved and converted into acids - selenium H 2 SeO3 and telluric H 2 TeO3. If sulfur dioxide 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 highly undesirable - we need them separately. Therefore, the process conditions are selected in such a way that, in accordance with the laws of chemical thermodynamics, selenium is primarily reduced first. This is helped by selecting the optimal concentration of hydrochloric acid added to the solution.
Tellurium is then deposited. The resulting 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 must first be purified from all these elements by chemical methods, then by distillation or zone melting. Naturally, tellurium is extracted from different ores in different ways.

Tellurium is harmful

Tellurium is being 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 tellurium aerosol “showed restlessness, sneezed, rubbed their faces, and became lethargic and drowsy.” Tellurium has a similar effect on people.

And myself tellurium and its connections can bring troubles of different “calibers”. They, for example, cause baldness, affect blood composition, and can block various enzyme systems. Symptoms of chronic poisoning with elemental tellurium are nausea, drowsiness, emaciation; the exhaled air acquires a foul, garlicky odor of alkyl tellurides.
In case of acute tellurium poisoning, serum with glucose is administered intravenously, and sometimes even morphine. Ascorbic acid is used as a prophylactic. But the main prevention is the reliable sealing of devices, automation of processes in which tellurium and its compounds are involved.

Element No. 52 brings a lot of benefits and therefore deserves attention. But working with it requires caution, clarity and, again, concentrated attention.
APPEARANCE OF TELLURIUM. Crystalline tellurium is most similar to antimony. Its color is silver-white. Crystals are hexagonal, the atoms in them form helical chains and are connected by covalent bonds to their nearest neighbors. Therefore, elemental tellurium can be considered an inorganic polymer. Crystalline tellurium is characterized by a metallic luster, although due to its complex of chemical properties it can rather be classified as a non-metal. Tellurium is brittle and quite easy to turn into powder. The question of the existence of an amorphous modification of tellurium has not been clearly resolved. When tellurium is reduced from telluric or telluric acid, a precipitate forms, but it is still not clear whether these particles are truly amorphous or just very small crystals.
BI-COLORED ANHYDRIDE. As befits an analogue of sulfur, tellurium exhibits valences of 2-, 4+ and 6+ and much less often 2+. Tellurium monoxide TeO can only exist in gaseous form and is easily oxidized to Te0 2. This is a white, non-hygroscopic, completely stable crystalline substance that melts without decomposition at 733 ° C; it has a polymer structure.
Tellurium dioxide is almost insoluble in water - only one part of Te0 2 per 1.5 million parts of water passes into the solution and a solution of weak telluric 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 are highly soluble in water. TeO3 anhydride, which forms telluric acid, is practically insoluble in water. This substance exists in two modifications - yellow and gray: α-TeO3 and β-TeO3. Gray tellurium 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 potassium.

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 contrary to their atomic weights. Indeed, the atomic mass of tellurium is 127.61, and that of iodine is 126.91. This means that iodine should not be behind tellurium, but in front 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. Mendeleev's close friend, the Czech chemist Boguslav Brauner, carefully checked the atomic weights of tellurium and iodine, but his data coincided with the previous ones. The validity of exceptions confirming the rule was established only when the periodic system was based not on atomic weights, but on nuclear charges, when the isotopic composition of both elements became known. Tellurium, unlike iodine, is dominated by heavy isotopes.
By the way, about isotones. There are currently 22 known isotopes of element No. 52. 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 tellurium is significantly less abundant on Earth than selenium, more minerals of element No. 52 are known than those of its counterpart. Tellurium minerals are of two types in composition: either tellurides or products of the oxidation of tellurides in the earth’s crust. Among the first are calaverite AuTe 2 and krennerite (Au, Ag) Te2, which are among the few natural gold compounds. Natural tellurides of bismuth, lead, and mercury are also known. Native tellurium is very rarely found 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 significance - all industrial tellurium is a by-product of processing ores of other metals.

T. I. Moldaver
Chemistry and Life No. 3, 1972, p. 17-21

"GODSON OF THE EARTH"

It is unlikely that anyone will believe the story about our contemporary - a sea captain, who, in addition, is a professional circus wrestler, a famous metallurgist and a consultant physician at a surgical clinic. In the world of chemical elements, such a variety of professions is a very common thing. Let us remember (even before talking about the main object of our story) iron in cars and iron in blood, iron is a magnetic field concentrator, and iron is an integral part of ocher... True, the “professional training” of elements sometimes took much more time than intermediate qualification yoga training. Likewise, element No. 52, which we are about to talk about, was used for many years only to demonstrate what it really is, this element named after our planet: tellurium - from tellus, which means “Earth” in Latin.

Element No. 52 was discovered almost two centuries ago. In 1782, mining inspector Franz Josef Müller von Reichenstein examined gold ore found in Semigorye, in what was then Austria-Hungary. It turned out to be so difficult to decipher the composition of this mineral that it was called Aurum problematicum - “problematic gold.” It was from this that Muller isolated a new metal. But there was no complete confidence that this metal was truly new. (It later turned out that Müller was wrong about something else: the element he discovered was new, but it would be a stretch to classify it as a metal.) To dispel doubts, Müller turned for help to a prominent specialist, the Swedish mineralogist and analyst T. Bergman. But he died before finishing the analysis of the sent substance - in those years, analytical methods were already quite accurate, but the analysis took a lot of time.

Other scientists also tried to understand the element discovered by Müller, but only 16 years after the discovery, Martin Heinrich Klaproth, one of the leading chemists of that time, irrefutably proved that tellurium was truly a new element. By the way, it was Klaproth who suggested the name “tellurium”.

TELLURIUM AND MEDICS

It is clear that after the discovery of an element, the search for its possible applications always begins. Apparently, based on the old principle, dating back to the times of atrochemistry, that the world is a pharmacy, the Frenchman Fournier tried to treat some serious diseases with tellurium, leprosy in particular. But without success. Only many years later was tellurium able to provide some services to doctors. More precisely, not tellurium itself, but salts of telluric acid - K 2 TeO 3 and Na 2 TeO 3 . They began to be used in microbiology as dyes that give a certain color to the bacteria being studied. In particular, with the help of tellurium compounds, the 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 permissible 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 and has a harmful effect on the nervous system.

These unpleasant properties did not prevent tellurium from being used in technology.

TELLURUM IN TECHNOLOGY

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; The service life of sulfuric acid production devices coated on the inside with a lead-tellurium alloy (0.5% Te) is twice as long as that of the same devices lined simply with lead. The addition of tellurium to copper and steel facilitates their machining.

In glass production, tellurium is used to give glass a brown color and a higher refractive index. In the rubber industry, it is sometimes used as an analogue of sulfur for the vulcanization of rubbers. However, these industries were not responsible for the jump in prices and demand for element No. 52.

This leap occurred in the early sixties of our century. Tellurium is a typical semiconductor, and a technological semiconductor. Unlike germanium and silicon, it melts relatively easily (melting point 449.8°C) and evaporates (boils at just below 1000°C). It is easy to obtain thin semiconductor films from it, which are of interest to modern microelectronics...

However, pure tellurium as a semiconductor is used to a limited extent - for the manufacture of certain types of transistors and in instruments that measure the intensity of gamma radiation. Sometimes a tellurium impurity is introduced into gallium arsenide (the third most important semiconductor after silicon and germanium) to create electronic-type conductivity in it.

The scope of application of some tellurides - compounds of tellurium with metals - is much broader. Tellurides of bismuth Bi 2 Te 3 and antimony Sb 2 Te 3 have become the most important materials for thermoelectric generators. To explain why this happened and what thermoelectric generators are, let’s make a short digression into the field of physics and history.

THREE EFFECTS

A century and a half ago (in 1821), the German physicist T. Seebeck discovered that in a closed electrical circuit consisting of different materials, an electromotive force is created if the contact points are at different temperatures.

Twelve years later, the Swiss J. Peltier discovered the opposite effect to the Seebeck phenomenon: when an electric current flows through a circuit composed of different materials, at the contact points, in addition to the usual Joule heat, a certain amount of heat is released or absorbed (depending on the direction of the current). The fact that in this case there is not a violation of Joule’s law, but a new physical effect, was proved by E. H. Lenz.

For about a hundred years, these discoveries remained 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 colleagues developed the theory of using 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, which use tellurides of bismuth, lead and antimony, provide energy to artificial Earth satellites, navigation and meteorological installations, and cathodic protection devices for main pipelines. The same materials help maintain the desired temperature in many electronic and microelectronic devices.

In recent years, another tellurium chemical compound with semiconductor properties, cadmium telluride CdTe, has attracted great interest. This material is used for the manufacture of solar cells, lasers, photoresistors, and radiation counters. Cadmium telluride is also famous for the fact that it is one of the few semiconductors in which the Han effect manifests itself.

The essence of the latter is that the 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.

TELLURIUM MINING

Tellurium is in the main subgroup of group VI of the periodic table, along with sulfur and selenium. These three elements are similar in chemical properties and often accompany each other in nature. But the share of sulfur in the earth's crust is 0.03%, selenium is 10-5%, and tellurium is even less - 10-7%. 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 this element in nature forms compounds with gold, silver, copper and other elements. More than 40 deposits of tellurium minerals have been discovered on our planet. But it is always mined together with selenium, or gold, or other metals.

In the USSR, copper-nickel tellurium-containing ores of Pechenga and Monchegorsk, tellurium-containing lead-zinc ores of Altai and other deposits are known.

When isolated from copper ore, tellurium is obtained at the stage of purifying blister copper by electrolysis. A sediment - sludge - falls at the bottom of the electrolyser. This is a very expensive intermediate product. To illustrate the composition of the sludge from one of the Canadian plants: 49.8% copper, 1.976% gold, 10.52% silver, 28.42% selenium and 3.83% tellurium.

But the most valuable components of the sludge must be separated. There are several options for solving this problem. Here's one of them.

The sludge is melted in a furnace and air is passed through the melt. Metals, except gold and silver, oxidize and turn into slag. Selenium and tellurium also oxidize, but their oxides are volatile; they are captured in special devices (scrubers), then dissolved and converted into acids - selenous H 2 SeO 3 and telluric H 2 TeO 3. If sulfur dioxide SO2 is passed through this solution, the following reactions will occur:

H 2 SeO 3 + 2SO 2 + H 2 O = Se + 2H 2 SO 4,
H 2 TeO 3 + 2SO 2 + H 2 O = Te + 2H 2 SO 4.

But it is not at all necessary for tellurium and selenium to fall out at the same time: we need them separately.

Therefore, the process conditions are selected in such a way that, in accordance with the laws of chemical thermodynamics, selenium is primarily reduced first. This is helped by selecting the optimal concentration of hydrochloric acid added to the solution.

Tellurium is then deposited. The resulting gray powder contains a certain amount of selenium and, in addition, sulfur, lead, copper, sodium, silicon, aluminum, iron, tin, antimony, bismuth, silver, magnesium, gold, arsenic, chlorine. And tellurium has to be cleaned - first by chemical methods, then by distillation or zone melting.

Tellurium is extracted differently from other ores, of course.

INDUSTRIAL POISON

Tellurium is being used more and more widely. This means that the number of people working with him is increasing. In the second chapter of our 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. I quote from a dissertation defended in 1962 and devoted to tellurium as an industrial poison. White rats injected with tellurium aerosol “showed restlessness, sneezed, rubbed their faces, and became lethargic and drowsy.” Tellurium has a similar effect on people.

Both tellurium itself and its compounds can cause troubles of different calibers. They, for example, cause baldness, affect the blood, and can block various enzyme systems. Symptoms of chronic poisoning with elemental tellurium are nausea, drowsiness, emaciation; the exhaled air acquires a foul, garlicky odor of alkyl tellurides.

In case of acute tellurium poisoning, serum with glucose, and sometimes even morphine, is administered intravenously. Ascorbic acid is used as a prophylactic. But the main prevention is reliable sealing of devices, automation of processes in which tellurium and its compounds are involved.

Element No. 52 brings a lot of benefits and therefore deserves attention. But at the same time, it requires caution, precision in work and, again, attention.

What you know and don't know about tellurium and its compounds

WHAT TELLURIUM LOOKS LIKE

Crystalline tellurium is most similar to antimony. Its color is silver-white. Crystals are hexagonal, the atoms in them form helical chains and are connected by covalent bonds to their nearest neighbors. Therefore, elemental tellurium can be considered an inorganic polymer. Crystalline tellurium is characterized by a metallic luster, although due to its complex of chemical properties it can rather be classified as a non-metal. Tellurium is brittle and quite easy to turn into powder. The question of the existence of an amorphous modification of tellurium has not been clearly resolved. When tellurium is reduced from telluric or telluric acid, a precipitate forms, but it is still not clear whether these particles are truly amorphous or just very small crystals.

BI-COLORED ANHYDRIDE

As befits an analogue of sulfur, tellurium exhibits valences of 2-, 4+ and 6+ and much less often 2+. Tellurium monoxide TeO can only exist in gaseous form and is easily oxidized to TeO 2. This is a white, non-hygroscopic, completely stable crystalline substance that melts without decomposition at 733°C, a polymer whose molecule is structured as follows:

Tellurium dioxide is almost insoluble in water: only one part of TeO 2 per one and a half million parts of water goes into solution. The result is a very dilute solution of weak telluric acid H 2 TeO 3 . Telluric acid H 6 TeO 6 also has weakly pronounced acidic properties. This formula (and not H 2 TeO 4)) was assigned to it after salts of the composition Ag 6 TeO 6 and Hg 3 TeO 6 were obtained. It dissolves well in water. But the telluric anhydride TeO 3 that forms it is practically insoluble in water. This substance exists in two modifications - yellow and gray: alpha-TeO 3 and beta-TeO 3. Gray tellurium anhydride, even when heated, is not affected by acids and concentrated alkalis. It is purified from the yellow variety by boiling the mixture in a concentrated KOH solution.

SECOND EXCEPTION

When the periodic table was created, tellurium and its neighbor iodine (as well as later argon and potassium) were placed in their places in groups VI and VII not in accordance with, but contrary to, atomic weights. Indeed, the atomic weight of tellurium is 127.61, and that of iodine is 126.91. This means that iodine should not be behind tellurium, but in front of it. Mendeleev, however, did not hesitate to place iodine in the seventh group and tellurium in the sixth. He believed that atomic weights were not determined accurately enough. Mendeleev's friend, Czech chemist Boguslav Brauner, carefully checked the atomic weights of these elements, but his data coincided with the previous ones. The validity of exceptions confirming the rule was established when the periodic table was based not on atomic weights, but on nuclear charges, and when the isotopic composition of both elements became known. Tellurium, unlike iodine, is dominated by heavy isotopes.

By the way, about isotopes. Currently, 22 isotopes of element No. 52 are known. Eight of them are stable, with mass numbers 120, 122, 123, 124, 125, 126, 128 and 130. The last two are the most common: their shares are 31.79 and 34.48%, respectively.

TELLURIUM MINERALS

Although tellurium is significantly less abundant on Earth than selenium, more tellurium minerals are known than its analogue. They are twofold in composition: either tellurides or products of the oxidation of tellurides in the earth’s crust. Among the first are calaverite AuTe 2 and krennerite (Au, Ag)Te 2. They are among the few naturally occurring gold compounds. Natural tellurides of bismuth, lead, and mercury are also known. Native tellurium is also very rarely found 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 significance - all industrial tellurium is obtained as a by-product.

Sensational news spread throughout the world in 1868. A new chemical element, previously unknown to science, was discovered. However, the sensation of this message was not so much that this element was new, but that it was discovered... not on Earth.

On August 18, 1868 in India, during a total solar eclipse, French astronomer Jules Jansen, observing the chromosphere of the Sun with a spectroscope, discovered a strange yellow line in its spectrum. This line did not belong to any of the known chemical elements. At the same time as J. Jansen, the same line was observed in England by astronomer Norman Lockyer. It was he who first guessed that this line belonged to a new chemical element. This is how helium was discovered. Helium was named after the ancient Greek god of the Sun, Helios. Later, this “solar gas” was discovered on Earth.

Helium is far from the only chemical element called by a heavenly name. Even in ancient times, the seven then known metals were associated with the seven “main” celestial bodies, which also included the Sun and the Moon.

Thus, gold symbolized the Sun, silver - the Moon, mercury was associated with Mercury, copper was a symbol of Venus, iron - Mars, tin - the metal of Jupiter, and lead - Saturn. So, we see that in ancient times some chemical elements were associated with the planets. They were even designated by the same symbols. However, many other elements discovered later received star names.

For example, the name of the element phosphorus, discovered in 1669, comes from the ancient Greek name for Venus, “Phosphoros,” which means “bringer of light.” The Greeks also called phosphorus all substances that can glow in the dark.

The name of another element is vanadium, which is also associated with the morning star. It was given to him in honor of the ancient Scandinavian goddess Vanadis, who was the personification of the planet Venus.

In 1781, William Herschel discovered the planet Uranus. And in 1789, an analytical chemist from Germany, Klaproth, discovered a new chemical element, which he named uranium, in honor of the recently discovered planet. Here is what Klaproth himself wrote about this: “...previously, the existence of only seven planets, corresponding to seven metals, was recognized, which were designated by the signs of the planets. In this regard, it is advisable, following tradition, to name the new metal after the newly discovered planet."

The first transuranic element produced artificially in 1940 was called neptunium. It was so named because the planet Neptune immediately follows Uranus in the solar system. And neptunium itself in the periodic table of chemical elements is located immediately after Uranus: the serial number of uranium is 92, and neptunium is 93. However, with neptunium everything turned out not as simple as with uranium.

Back in 1868, the German scientist Clemens Winkler discovered a new element and proposed calling it neptunium. Winkler, like many of his contemporaries, was then still strongly impressed by Urban Le Verrier’s brilliantly confirmed prediction in 1846 about the existence of another planet in the family of the Sun. The planet was named Neptune. But soon K. Winkler had to abandon the original name of the new element. He learned that one of the elements had already been named neptunium. In 1850, the chemist Hermann announced the discovery of a new metal, which he called neptunium. But, alas, the discovery did not take place; the “new” metal turned out to be identical to niobium. Thus, of all this trinity of neptuniums, in the end, only one remained in the periodic table.

In 1930, American astronomer Clyde Tombaugh discovered the planet Pluto. And at the end of 1940, a new element was discovered at the University of California. You probably already guessed how it was named! Yes, it was called plutonium. It was given this name because it comes immediately after neptunium in the periodic table of chemical elements, just as Pluto comes after Neptune in the solar system. However, the names of not only major planets are reflected in the names of chemical elements.

On New Year's Eve, January 1, 1801, Italian astronomer Giuseppe Piazzi discovered the first small planet, which was soon dubbed Ceres. And just two years later, in 1803, a new element was discovered, named after the asteroid Ceres, cerium. It was also called cererium, but this designation seemed inconvenient and difficult for scientists to pronounce, and therefore it did not take root.

In January 1798, the discoverer of the element uranium, Klaproth, spoke to the scientific meeting of the Berlin Academy of Sciences with a message about his discovery of a new chemical element, which, in his words, was obtained, in his words, “from Mother Earth.” Therefore, he named it tellurium, from the Latin word Tellus - Earth, planet. And in 1817, Jens Berzelius discovered an element that turned out to be very similar in its properties to tellurium. J. Berzelius wrote: “In accordance with this analogy, I named the new element selenium, from the Greek Selene (Moon), since tellurium is named after Tellus - our planet.” And the fact that selenium is “very similar in its properties to tellurium” is deeply symbolic. Such proximity of these elements makes us remember that the Earth and the Moon are not just two cosmic bodies, but a double planet Earth-Moon.

In chemistry, as in any other science, the path to truth is not always smooth. It lies through the thorns of doubt and delusion. And it is not surprising that many elements that were thought to be newly discovered ended up being false. And although the discoveries of these elements were erroneous, history has preserved for us the names of these “unapproved” elements, including astronomical ones.

For example, vicissitudes similar to those that occurred with neptunium did not bypass the names of elements associated with asteroids.

On September 2, 1804, the German astronomer Karl Harding discovered the asteroid Juno, and in 1811, the chemist Thomson announced the discovery of a new element, which he proposed to call junonium. Another junonium was “discovered” in 1818 by Karsten, but in the end these discoveries were not confirmed. The same fate befell another element, which they wanted to call vestalium or vestia, in honor of the asteroid Vesta discovered in 1807 by Heinrich Olbers.

After the discovery of helium, chemists believed for some time that this gas actually consists of a mixture of two gases, one of which was proposed to be called “asterium,” that is, “stellar.” They also thought that there was a certain gas intermediate between hydrogen and helium. This hypothetical gas also had a star name - asturium. It has been suggested that Asturias can be observed in the spectra of stars, the solar corona and cosmic dust. But in the end everything fell into place.

Another hypothetical element, corona, was so named because it was thought that it could be observed in the spectrum of the solar corona. This is what D.I. Mendeleev himself thought. In his opinion, “this hitherto imaginary element” was supposed to be an analogue of helium.

In 1907, Auer von Welsbach gave two new elements the names Aldebaranium, after the star Aldebaran (a Taurus), and Cassiopeia, after the constellation Cassiopeia. But, as it turned out, such elements simply do not exist; they were discovered by mistake and were in fact other, already known elements. And at the beginning of this century, many scientists believed in the existence of the element nebula, which supposedly should be in stellar nebulae (Nebula - nebula). But today this hypothesis has already become history.

Yes, discovering a new chemical element is not easy. But science does not stand still. And there are still so many painstaking searches, mistakes, misconceptions, doubts ahead, but so many secrets and amazing discoveries.

"What's in a name?" - the poet once said. Indeed, does it really matter what a particular chemical element is called? After all, essentially they are all cosmic. Because they are everywhere, in all corners of the Universe.

Etymology of names of chemical elements.

The science of etymology deals with the origin of a word and the description of its relationships 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 class we will look at the origin of some chemical elements. We simply 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.

Uranium, Neptunium, Plutonium

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

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, what was believed to be a new metal was discovered in a mineral brought to Europe from the United States, it was suggested by astronomers that it should be called neptunium.

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 name the next element after neptunium plutonium; it was obtained in 1940 by bombarding uranium with deuterium nuclei.

Cerium

Elements named after mythical heroes

Cadmium

Discovered in 1818 by the German chemist and pharmacist Friedrich Strohmeyer in zinc carbonate, from which medicines were obtained at a pharmaceutical factory. Since ancient times, the Greek word “kadmeia” has been used to describe carbonate zinc ores. The name goes back to the mythical Cadmus (Cadmos) - the hero of Greek mythology, the brother of Europe, the king of the Cadmean land, the founder of Thebes, the slayer 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 the territory of modern Massachusetts in the 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 an 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, become saturated) in any acid. The “legislator” in the chemistry of those times, the Swedish chemist Jene Jakob Berzelius, proposed calling the metal contained in this oxide tantalum.

Promethium

In 1947, American researchers J. Marinsky, L. Glendenin and C. Coryell separated chromatographically the fission products of uranium in a nuclear reactor. Coryell's wife suggested calling the discovered element promethium, after Prometheus, who stole fire from the gods and gave it to people. This emphasized the formidable power contained in 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 Swedish chemist Nils Sefström in blast furnace slag. Named after the Old Norse goddess of beauty Vanadis, or Vana-Dis. In this case, it also turned out that vanadium had been discovered before, and even more than once - by the Mexican mineralogist Andree Manuel del Rio in 1801 and by the German chemist Friedrich Wöhler shortly before Sefström's discovery. But del Rio himself abandoned his discovery, deciding that he was dealing with chromium, and Wöhler’s illness prevented him from completing the work.

Helium

On November 13, 1968, Italian astronomer Angelo Secchi noticed a “remarkable line” in the solar spectrum near the famous yellow sodium D line. He suggested that this line was emitted by hydrogen under extreme conditions. It was only in January 1871 that Lockyer suggested that this line might belong to a new element. The word “helium” was first used by the President of the British Association for the Advancement of Science, William Thomson, in a speech 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 kleveite when it was treated with acid and, with the help of Lockyer, studied it using the spectral method. As a result, the “solar” element was discovered on Earth.

Elements named after states and geographical features

Ruthenium

This platinum group metal was discovered by K. K. Klaus in Kazan in 1844 when he analyzed the so-called factory platinum deposits. Klaus isolated a new metal in the form of a sulfide and proposed to call it ruthenium in honor of 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– in honor of a city in the USA

Dubniy– 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 ancient Latin name Holmia)

Elements named after researchers

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 named this oxide gadolinium earth (Gadolinia), and when the metal was isolated from it in 1896, it was called gadolinium. This was the first time a chemical element was named after a scientist.

Fermium and einsteinium

In 1953, in the products of the thermonuclear explosion that the Americans carried out in 1952, isotopes of two new elements were discovered, which were named fermium and einsteinium - in honor of 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. He was named after Pierre and Marie Curie.

Mendelevium

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

Nobelium

Its discovery was first reported in 1957 by an international group of scientists working in Stockholm, who proposed naming the element in honor of Alfred Nobel. Later it turned out that the results obtained were erroneous. The first reliable data on element 102 were obtained by the group of G.N. Flerov in 1966. Scientists proposed renaming the element in honor of the French physicist Frederic Joliot-Curie and calling it joliotium (Jl). As a compromise, there was a proposal to name the element Flerovium - in honor of Flerov. The question remained open, and for several decades the Nobelium symbol was placed in parentheses. This was the case, 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 publications, the Nobelium symbol was freed from brackets.

Lawrence

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 and inventor of the cyclotron. The Berkeley National Laboratory is named after Lawrence.

Rutherfordium

The first experiments to obtain element 104 were undertaken by Ivo Zvara and his colleagues back in the 60s. G.N. Flerov and his co-workers reported obtaining 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. Kurchatova. American researchers who synthesized this element in 1969 used a new identification technique, believing that the previously obtained results 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 the opening should be shared by both groups.

Kurchatovy

According to Seaborg's theory about the similarity of the structure of the electron shells of lanthanides and transuranium elements, element 104, being an analogue of hafnium, should belong not 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.

Borius

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.