The history of the discovery of selenium. Tellurium History Chem Element Honoring Earth

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

"EARTH'S CROSS"

Hardly anyone will believe the story about our contemporary - the sea captain, who, in addition, is a professional circus wrestler, a famous metallurgist and a consultant doctor of a surgical clinic. In the world of chemical elements, such a variety of professions is a very common thing. Let us recall (even before talking about the main object of our story) iron in cars and iron in blood, an iron concentrator of the magnetic field, and iron is an integral part of ocher ... True, it sometimes took much longer to "professionalize" the elements than to training yoga of average skill. So element number 52, which we are about to tell, was used for many years only in order to demonstrate what it really is, this element, named after our planet: tellurium - from tellus, which in Latin means "Earth".

Element 52 was discovered almost two centuries ago. In 1782, mining inspector Franz Josef Müller von Reichenstein investigated the gold-bearing 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 named Aurum problematicum - "problematic gold". It was from him that Müller isolated the new metal. But there was no complete certainty that this metal was really new. (Subsequently, it turned out that Müller was wrong about something else: the element he discovered was still new, but it can hardly be attributed to the number of metals.) To dispel doubts, Müller turned to a prominent specialist, Swedish mineralogist and analyst T. Bergman for help. But he 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 lot of time.

Other scientists tried to figure out the element discovered by Müller, but only 16 years after the discovery, Martin Heinrich Klaproth - one of the greatest chemists of that time - irrefutably proved that tellurium is really a new element. By the way, the name "tellurium" was suggested by Klaproth.

TELLURIUM AND MEDIC

It is clear that after the discovery of an element, the search for its possible applications always begins. Apparently, proceeding from the old - even from the times of iatrochemistry - the principle that 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 services to doctors. More precisely, not tellurium itself, but telluric acid salts - K 2 TeO 3 and Na 2 TeO 3. They began to be used in microbiology as dyes that impart a certain color to the studied bacteria. In particular, with the help of tellurium compounds, diphtheria bacillus is reliably isolated from the mass of bacteria. If not in treatment, then at least in diagnostics, element No. 52 was useful to doctors.

But sometimes this element, and even more some of its compounds, add hassle to doctors. Tellurium is quite toxic. In our country, the maximum permissible 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 that H 2 Te should be like hydrogen sulfide. It irritates the bronchi, has a harmful effect on the nervous system.

These unpleasant properties did not prevent tellurium from entering the technique.

TELLURIUM IN TECHNOLOGY

Metallurgists are interested in tellurium because even its 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 the apparatus of sulfuric acid production, coated from the inside with a lead-tellurium alloy (0.5% Te), is twice as long as that of the same apparatus, simply lined 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, as an analogue of sulfur, it is sometimes used for vulcanizing rubbers. However, these industries were not responsible for the jump in prices and demand for item # 52.

This leap took place in the early sixties of our century. Tellurium is a typical semiconductor, and the semiconductor is technologically advanced. Unlike germanium and silicon, it melts relatively easily (melting point 449.8 ° C) and evaporates (boils at a temperature 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 transistors of some types and in devices that measure the intensity of gamma radiation. Sometimes tellurium impurity is introduced into gallium arsenide (the third most important semiconductor after silicon and germanium) in order to create electron-type conductivity in it.

The fields of application of some tellurides - tellurium compounds with metals are much broader. Bismuth tellurides 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 small 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 an electromotive force is created in a closed electrical circuit consisting of different materials if the contact points are at different temperatures.

Twelve years later, the Swiss J. Peltier discovered an effect opposite to the Seebeck phenomenon: when an electric current flows through a circuit made up of different materials, a certain amount of heat is released or absorbed (depending on the direction of the current) in the places of contacts, in addition to the usual Joule heat. 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, no more. And it will not be an exaggeration to assert that a new life of both these effects began after Academician A.F. Ioffe and his co-workers 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, in which bismuth, lead and antimony tellurides are used, provide energy to artificial earth satellites, navigational 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 chemical compound of tellurium with semiconducting properties, cadmium telluride CdTe, has been of great interest. This material is used for the manufacture of solar cells, lasers, photoresistors, and radioactive radiation counters. Cadmium telluride is also famous for being one of the few semiconductors in which the Hahn effect is manifested.

The essence of the latter lies in the fact 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 applications in radar technology.

MINING TELLURIUM

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 - 10-5%, 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 along with selenium, or gold, or other metals.

Copper-nickel tellurium-bearing ores of Pechenga and Monchegorsk, tellurium-bearing lead-zinc ore of Altai and other deposits are known in the USSR.

When separating from copper ore, tellurium is obtained at the stage of purification of blister copper by electrolysis. A sludge precipitates at the bottom of the cell. This is a very expensive intermediate product. Let us give, for illustration, 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 is one of them.

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

H 2 SeO 3 + 2SO 2 + H 2 O \u003d Se + 2H 2 SO 4,
H 2 TeO 3 + 2SO 2 + H 2 O \u003d Te + 2H 2 SO 4.

But it is not at all necessary that tellurium and selenium fall out simultaneously: we need them separately.

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

Then tellurium is besieged. The fallen 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 from other ores, of course, differently.

INDUSTRIAL POISON

Tellurium is being used more and more. This means that the number of those working with him is also increasing. In the second chapter of our story about element number 52, we have 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 am citing a dissertation defended in 1962 on tellurium as an industrial poison. White rats, which were injected with tellurium aerosol, "showed anxiety, sneezed, rubbed their faces, became lethargic and drowsy." Tellurium has a similar effect on humans.

Tellurium itself and its compounds can bring 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 - nausea, drowsiness, emaciation; exhaled air takes on a nasty garlic smell of alkyl tellurides.

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

Element 52 is very useful and therefore deserves attention. But at the same time it requires caution, precision in work and, again, attention.

What You Know and What You Don't Know About Tellurium and Its Compounds

HOW TELLURUS LOOKS

Crystalline tellurium is most similar to antimony. Its color is silvery white. Crystals are hexagonal, the atoms in them form spiral chains and are linked by covalent bonds with the nearest neighbors. Therefore, elemental tellurium can be considered an inorganic polymer. Crystalline tellurium is characterized by a metallic luster, although by its complex of chemical properties it can rather be attributed to non-metals. Tellurium is fragile and can be easily powdered. 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 is formed, but it is still not clear whether these particles are truly amorphous or just very small crystals.

TWO-COLOR ANHYDRID

As befits an 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 TeO 2. It is a white, non-hygroscopic, completely stable crystalline substance that melts without decomposition at 733 ° C, a polymer whose molecule is structured like this:

Tellurium dioxide almost does not dissolve in water: only one part of TeO 2 per one and a half million parts of water goes into solution. A very dilute solution of a weak telluous acid H 2 TeO 3 is obtained. Weakly expressed acidic properties and telluric acid H 6 TeO 6. This formula (and not H 2 TeO 4,)) was assigned to it after the 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 practically does not dissolve in water. This substance exists in two modifications - yellow and gray: alpha-TeO 3 and beta-TeO 3. Even when heated, gray telluric anhydride 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 (just like later argon and potassium) were put in their places in groups VI and VII, not in accordance with, but in spite of atomic weights. Indeed, the atomic weight of tellurium is 127.61, and that of iodine is 126.91. This means that iodine would have to stand not 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, the Czech chemist Bohuslav Brauner, carefully checked the atomic weights of these elements, but his data coincided with the previous ones. The legitimacy of the exceptions confirming the rule was established when the basis of the periodic table was not atomic weights, but the charges of nuclei, and when the isotopic composition of both elements became known. Tellurium, in contrast to iodine, is dominated by heavy isotopes.

By the way, about isotopes. Now 22 isotopes of element No. 52 are known. The stable ones are eight 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.

MINERALS TELLURIUM

Although tellurium is significantly less abundant on Earth than selenium, there are more tellurium minerals known than its counterpart. In composition, they are twofold: either tellurides, or oxidation products 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 natural gold compounds. Natural tellurides of bismuth, lead, and mercury are also known. Native tellurium is also 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 obtained along the way.

Hardly anyone will believe the story of the sea captain, who is, moreover, a professional circus wrestler, a famous metallurgist and a consultant doctor at a surgical clinic. In the world of chemical elements, such a variety of professions is a very common phenomenon, and the expression of Kozma Prutkov is inapplicable to them: "A specialist is like a gumboil: his completeness is one-sided." Let us recall (even before talking about the main object of our story) iron in cars and iron in blood, iron is a concentrator of the magnetic field and iron is an integral part of ocher ... True, it sometimes took much more time to "professionalize" the elements than to prepare yoga of average skill. So the element number 52, which we are about to tell, was used for many years only in order 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 Josef Müller (later Baron von Reichenstein) investigated the gold-bearing ore found in Semigorye, on the territory of what was then Austria-Hungary. It turned out to be so difficult to decipher the composition of the ore that it was named Aurum problematicum - "doubtful gold". It was from this "gold" that Muller singled out a new metal, but there was no complete certainty that it was really new. (Subsequently, 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 stretch.)

To dispel doubts, Müller turned to a prominent specialist, the Swedish mineralogist and analytical chemist Bergman.
Unfortunately, the scientist died before he could finish the analysis of the sent substance - in those years the analytical methods were already quite accurate, but the analysis took a lot of time.
Other scientists tried to study the element discovered by Müller, 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 suggested the name "tellurium" for it.
As always, following the discovery of the element, the search for its applications began. Apparently, proceeding from the old, even from the time of iatrochemistry, the principle - 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 doctors with some "minor services". More precisely, not tellurium itself, but the salts of telluric acid K 2 TeO 3 and Na 2 TeO 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, diphtheria bacillus is reliably isolated from the mass of bacteria. If not in treatment, then at least in diagnostics, element No. 52 was useful to doctors.
But sometimes this element, and even more some of its compounds, add hassle to doctors. Tellurium Fairly toxic. In our country, the maximum permissible concentration of tellurium in the air is 0.01 mg / m3. The most dangerous of the tellurium compounds 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 like hydrogen sulfide. It irritates the bronchi, has a harmful effect on the nervous system.
These unpleasant properties did not prevent tellurium from entering technology, acquiring many "professions".
Metallurgists are interested in tellurium because even its 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 devices 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 the same devices, simply lined 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, as an analogue of sulfur, it is sometimes used for vulcanizing 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 the semiconductor is technologically advanced. Unlike germanium and silicon, it melts relatively easily (melting point 449.8 ° C) and evaporates (boils at a temperature just below 1000 ° C). Hence, it is easy to obtain thin semiconductor films from it, which are of particular interest in 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 an electronic type of conductivity in it.
The area of \u200b\u200bapplication of some tellurides - tellurium compounds with metals is much broader. Bismuth tellurides 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 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 an electromotive force (called thermo-EMF) is created in a closed electric circuit consisting of different materials, contacts between which are at different temperatures. 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, in the places of contacts, 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 will not be an exaggeration to assert that a new life of both these effects began after Academician A.F. Ioffe and his co-workers 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, in which bismuth, lead and antimony tellurides are used, provide energy to artificial earth satellites, navigational 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 chemical compound of tellurium with semiconducting properties, cadmium telluride CdTe, has been of great interest. This material is used for the manufacture of solar cells, lasers, photoreflection sensors, and radioactive radiation counters. 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 is that the very introduction of a small plate of a corresponding semiconductor into a sufficiently strong electric field leads to the generation of high-frequency radio emission. The Hahn effect has already found applications in radar technology.
In conclusion, we can say that quantitatively, the main "profession" of tellurium is 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 share of sulfur in the earth's crust is 0.03%, selenium is only 10-5%, tellurium is still 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.
Copper-nickel tellurium-bearing ores of Pechenga and Monchegorsk, tellurium-bearing lead-zinc ores of Altai and a number of other deposits are known in Russia.

Tellurium is isolated from copper ore at the stage of purification of blister copper by electrolysis. At the bottom of the electrolyzer, sediment - sludge - flows. This is a very expensive intermediate product. Let us give, for illustration, 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 most valuable components of the sludge must be separated, and there are several ways for 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, are oxidized and pass 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 - selenium H 2 SeO3 and telluride 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, predominantly selenium is reduced first. This is facilitated by the selection of the optimal concentration of hydrochloric acid added to the solution.
Then tellurium is besieged. The fallen 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 in different ways from different ores.

Tellurium is harmful

Tellurium is used more and more widely and, therefore, the number of those working with it is increasing. In the first part of the story about element No. 52, we have 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, which were injected with tellurium aerosol, "showed anxiety, sneezed, rubbed their faces, became lethargic and drowsy." Tellurium has a similar effect on humans.

And myself telluriumand its compounds can bring misfortunes of different calibers. They, for example, cause baldness, affect blood composition, and can block various enzyme systems. Symptoms of chronic poisoning with elemental tellurium - nausea, drowsiness, emaciation; exhaled air takes on a nasty garlic smell of alkyl tellurides.
In acute poisoning with tellurium, serum with glucose is administered intravenouslyand sometimes even morphine. As a prophylactic agent, ascorbic acid is used. But the main prevention is reliable sealing of devices, automation of processes involving tellurium and its compounds.

Element 52 is very useful and therefore deserves attention. But working with him requires caution, clarity and, again, focused attention.
APPEARANCE OF TELLURIUM. Crystalline tellurium is most similar to antimony. Its color is silvery white. Crystals are hexagonal, the atoms in them form spiral chains and are linked by covalent bonds with the nearest neighbors. Therefore, elemental tellurium can be considered an inorganic polymer. Crystalline tellurium is characterized by a metallic luster, although by its complex of chemical properties it can rather be attributed to non-metals. Tellurium is fragile and can be easily powdered. 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 is formed, but it is still not clear whether these particles are truly amorphous or just very small crystals.
TWO-COLOR ANHYDRID. As befits an 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 TeO 2. It is a white, non-hygroscopic, completely stable crystalline substance that melts without decomposition at 733 ° C; it has a polymeric structure.
Tellurium dioxide almost does not dissolve in water - only one part of TeO 2 per 1.5 million parts of water passes into the solution and a solution of weak tellurous acid H 2 TeO 3 of negligible concentration is formed. The acidic properties of telluric acid are also weakly expressed.

H 6 TeO 6. This formula (and not Н 2 TeO 4 was assigned to it after salts of the composition Ag 6 Te0 6 and Hg 3 Te0 6, which are readily soluble in water, were obtained. modifications - yellow and gray: α-TeOs and β-TeOs. Gray telluric anhydride is very stable: even when heated, acids and concentrated alkalis do not act on it. It is purified from the yellow variety by boiling the mixture in concentrated potassium hydroxide.

SECOND EXCEPTION. When creating the periodic table, Mendeleev put tellurium and the 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 should have stood not behind tellurium, but ahead of it. Mendeleev, however, did not doubt the right
the validity 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 the exceptions confirming the rule was established only when the basis of the periodic table was not atomic weights, but the charges of nuclei, when the isotopic composition of both elements became known. Tellurium, in contrast to iodine, is dominated by heavy isotopes.
By the way, about isotones. Now there are 22 known isotopes of element number 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.

MINERALS TELLURIUM. Although tellurium is much less abundant on Earth than selenium, there are more minerals known for element 52 than its counterpart. By their composition, tellurium minerals are twofold: either tellurides, or the oxidation products 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, 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 other metal ores.

Geographic names:
Gallium and Francium - in honor of France, the homeland of the scientists who discovered them,
Scandium and Thulium - in honor of Scandinavia (ancient Thule), the birthplace of the scientists who discovered them - Sweden,
Germanium- in honor of Germany, the birthplace of the scientist who discovered it,
Ruthenium- in honor of Russia, the birthplace of the scientist Karl Klaus who discovered it (now I would probably name it in honor of Estonia, but then Tartu was in Russia),
Polonium- in honor of Poland, the birthplace of M. Curie-Sklodowska, who discovered it,
Nihoniy- in honor of Japan, one of the homelands of the scientists who synthesized it,
Copper(Cuprum) - in honor of Cyprus, rich in copper deposits,
Hassius and Darmstadt- in honor of the land of Hessen, in which Darmstadt is located, and Darmstadt itself, where they were discovered,
Lutetium- in honor of Paris (lat.Lutetia Parisorum), the birthplace of the scientist who discovered it,
Hafnium- in honor of Copenhagen (lat.Hafnia), the scientists who discovered it worked at a local university,
Berkelium and California - in honor of the city of Berkeley and the state of California, the scientists who discovered it worked at a local university,
Dubny and Muscovy - in honor of Dubna, where it was opened, and the Moscow region, in which Dubna is located,
Livermorium- in honor of Livermore, in the local laboratory it was opened,
Tenessine- in honor of Tennessee, for there is a good, good Oak Ridge laboratory there,
Holmium- in honor of Stockholm, the birthplace of the scientist who discovered it,
Ytterbium (and Yttrium, Terbium and Erbium) - in honor of the village of Ytterby in Sweden, near which rich deposits of REE were found,
Strontium- in honor of the village of Strontian in Scotland, where there was a lead mine, in which the strontium mineral was first discovered,
Rhenium- in honor of the Rhine, opened by the Germans.
Bonus:
Selenium and Tellurium - named after the moon and earth, respectively.
Europium and Americium - in honor of Europe and America.

Named elements:
Gadolinium, in honor of Yu. Gadolin, who studied the gadolinite mineral and discovered that it contains some incomprehensible elements (in fact, half of the REE was then isolated from it).
Samarium- in honor of V.E. Samarsky-Bykhovets, a mining engineer who provided the scientists with the ore from which the element was isolated,
Curium- in honor of P. and M. Curie, who studied radioactive elements and radioactivity as such,
Einsteinium- in honor of A. Einstein, since he is a great physicist,
Fermi- in honor of E. Fermi, since he was a great physicist and studied radioactivity,
Mendelevium- in honor of D.I. Mendeleev, since he was a great chemist and discovered the periodic law, and even predicted a bunch of elements,
Nobelium- in honor of A. Nobel, because with his help many great physicists and chemists received a lot of money,
Lawrence- in honor of E. Lawrence, since he invented the cyclotron, on which all these new elements do,
Rutherfordium- in honor of E. Rutherford, since he was a great physicist and studied the structure of the atom,
Seaborgium- in honor of G. Seaborg, since the name of the country, state, city and laboratory in which he and his group discovered the elements, the new elements had already been named, and I did not want to give names in honor of someone else,
Boriy- in honor of N. Bohr, since he was a great physicist and studied the structure of the atom,
Meitnerium- in honor of L. Meitner, since she is a great physicist,
Roentgenium- in honor of V.K. Roentgen, since he was a great physicist,
Copernicus- in honor of N. Copernicus, since he created a heliocentric model of the solar system,
Flerovium- in honor of G.N. Flerov, whose laboratory in batches synthesized new elements in Dubna, like Seaborg in California,
Hovhanneson- in honor of Yu.Ts. Hovhannisyan, because he is a great nuclear physicist and also in Dubna.
Bonus:
Cobalt and Nickel - Kobold and Nicolaus, respectively, gnome and malevolent man, the spirit of the mine.

Element number 52 has been 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.This element was discovered almost two centuries ago. In 1782, mining inspector Franz Josef Müller (later Baron von Reichenstein) investigated the gold-bearing ore found in Semigorye, on the territory of what was then Austria-Hungary. It turned out to be so difficult to decipher the composition of the ore that it was named Aurum problematicum - "doubtful gold". It was from this “gold” that Müller singled out a new metal, but there was no complete confidence that it was really new.

(Subsequently, it turned out that Müller was wrong about something else: the element he discovered was new, but it can only be attributed to the number of metals with a great 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 what was sent - in those years, analytical methods were already quite accurate, but the analysis took a very long time. The element discovered by Mueller was tried to be studied andothersscientists, however, only 16 years after its discoveryMartin Heinrich Klaproth - one of the greatest chemists of the time - irrefutably proved that this element was actually new, and suggested the name "tellurium" for it.

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

But sometimes this element, and even more some of its compounds, add to the doctors' hassle. quite toxic. In our country, the maximum permissible concentration of tellurium in the air is 0.01 mg / m 3. The most dangerous of the tellurium compounds 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, meaning chit.H2Te should be like hydrogen sulfide. He is irritatedreaps bronchi,harmful to the nervous system.These unpleasant properties did not prevent tellurium from entering technology, acquiring many "professions".Metallurgists are interested in tellurium because even its small additions to lead greatly increase the strength and chemical resistance of this important metal. alloyed with tellurium is used in the cable and chemical industries.

Thus, the service life of devices 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 the same devices, simply lined with lead. The addition of tellurium to copper and steel facilitates their machining. In the glass industry, tellurium is used to give glass a brown color and a higher refractive index. In the rubber industry, as an analogue of sulfur, it is sometimes used for vulcanizing rubbers.

Article on the topic of Tellurium history

The discoveries were undoubtedly the periodic table and the law. It was she who made it possible to streamline the elements known at that time, bring into the system all available knowledge and understand the patterns of change in the manifested properties.

When it was created by Mendeleev, only 63 types of atom were known. Today there are already 118 of them, and each has its own place, has a number of properties and characteristics. Naturally, your name. Many chemical elements, named after scientists, countries, cities, planets, and so on, are very important in the life of living beings.

Periodic table structure

There are different options for such tables:

long-period;
short-period;
extra long.

In total, there are over a hundred different options for graphical display of the periodic dependence of atoms. And until now, scientists are proposing all the new ways.

Most often they use the long-period and short-period table options. Each chemical particle has its own cell, which reflects basic information about it. So, you can see a brief electronic configuration of the outer shell of an atom, the serial number, atomic mass (the average value between all types of isotopes) and, of course, the name. In our country - in translation into Russian, in others - in their language. How is this or that name of the atom formed and on what does it depend?

Many chemical elements are named after scientists, some - in honor of cities and countries, geographical objects, some more - in honor of mythical heroes, gods, objects of the Cosmos. Many are named according to the color they form or the color that the substance gives during spectrometric analysis.

Properties of chemical elements

It is very interesting that all the cells of the table carry information not only about this or that structural link, but also about its properties. Looking at the position in, you can name the oxidation state, predict the physical and chemical properties, determine the activity and nature of the compounds.

In total, several properties can be distinguished that are characteristic of atoms and their simple and complex substances:

oxidative;
restorative;
acidic;
basic;
amphoteric;
metal;
non-metallic.

Only by the cell in which the particle is located, it is possible to classify it according to all the listed properties. However, this is not only important and interesting. Sometimes the name of an element is very unusual, which speaks about the properties, and about its compounds, and about the discoverer.

Formation of names

As mentioned above, many countries, cities and planets, etc., are very important for living beings, as they are part of their body. This also applies to humans.

For example, carbon and hydrogen. The name itself speaks for itself: "giving birth to coal" and "giving birth to water", respectively. And what kind of organism is without these structures? None is alive, because carbon is the basis of organic compounds, which means protein, nucleic acids, carbohydrates and other vital substances.

Every first grader knows that life is impossible without water. The properties of chemical elements are also often reflected in the name. For example, oxygen is "giving birth to acids". This means that this element will have oxidizing properties.

Or nitrogen - "lifeless" in Latin. Why? This gas does not support life on Earth; living beings are threatened with death in its atmosphere. And there are many such examples out of 118.

Elements named after scientists

What chemical elements are named after scientists? Those that the discoverer wanted to name after himself or another. After all, he owns the right to give a name. Pleasant enough prerogative.

The formulas of chemical elements are formed from their Latin names, and the names themselves - from the desire of people-scientists. For example, many wanted to immortalize the names of the great Russian and foreign chemists in the names of atoms. And they succeeded. Let's look at the main examples that illustrate which chemical elements are named after scientists.

Samarium - Sm. Formed from the mineral samarsite. And the breed itself is in honor of the great Russian soldier, Colonel Samara. This man made a great contribution to the development of the mining business, as he was an inspector of mines and mines.
Gadolinium - Gd. It got its name thanks to the Finnish chemist Johan Gadolin, who at one time discovered the element yttrium.
Einsteinium - Es, has the same designation as other formulas of chemical elements: from the Latin spelling of the surname of the great Albert Einstein.
Fermi - Fm. Received the name in honor of the great scientist, the creator of nuclear and neutron physics Enrico Fermi. Nobel Prize Nominee for Endless Research and Achievement.
Mendelevium - Md. This element perpetuates the name of Dmitry Ivanovich Mendeleev, already well-known throughout the world.
Nobelium - No. Received the name from the Swedish chemist, inventor, discoverer of dynamite. It is he who is the author of the Nobel Prize in the field of merit in science. He bequeathed his wealth to payments to talented scientists.
Lawrence - Lr. It is a tribute to Ernest Lawrence, one of the creators of the atomic bomb, a brilliant scientist who made a great contribution to the development of physics, especially its nuclear section.
Kurchatoviy - Ku. Named after Igor Vasilyevich Kurchatov, a brilliant Soviet scientist, creator of our, Russian, atomic bomb.
Nielsborium - Ns. Thanks to Niels Bohr, one of the founders of quantum mechanics and modern physics.

These are practically all chemical elements named after scientists. The list does not include just one element, which is discussed below.

Women Scientists and Chemistry

There are chemical elements named after female scientists. But so far, unfortunately, there is only one. And there are not many women chemists. This is curium - Km. It was named in honor of which, together with her husband Pierre, a physicist, made the discovery of the phenomenon of radiation and carried out a lot of work on this basis. The couple were awarded the Nobel Prize for their services.

Discovery of the element polonium - Po.
Discovery and study of the piezoelectric effect.
Discovery of the element radium - Ra.

Thus, we reviewed the entire list in which chemical elements are named after scientists. So far there are only 10 of the known 118, but time does not stand still. Scientists are constantly researching isotopes, nuclear reactions are carried out and all new compounds and elements are synthesized. Therefore, it is possible that this list will be replenished with great names.

Country and city names in elements

In addition to what are called chemical elements in honor of scientists, there are a number of options for their designation. For example, many have immortalized cities and countries.

Magnesium - Mg. On the coast of the Aegean Sea there is the city of Magnesia. It was he who became the prototype for the name of this element.
Scandium - Sc. Perpetuated Scandinavia, which reflects both Latin and Russian names.
Copper - Cu. In Latin it is pronounced as cuprum, hence the explanation for the name: in honor of the island of Cyprus.
Gallium - Ga. In honor of the country of France, as in Latin its name is "gallium".
Germanium - Ge. Obviously named after the country of Germany.
Strontium - Sr. Not only countries and cities, but also villages are honored to be immortalized in the name of the chemical element. Named after the village of Stronshian in Scotland.
Yttrium - In honor of the village of Ytterby in Sweden.
Ruthenium - Ru. Russia is a symbol of this element.
Europium - Eu. In honor of all of Europe.
Lutetium - Lu. In Latin, "lutetia" is Paris, which is why the element is named after this beautiful city.
Hafnium - Hf. In honor of Copenhagen, which sounds like "hafnia" in Latin.
Polonius - Po. In honor of Poland.
Americium - Am. In honor of America.
California - Cf. In honor of the American state of California.
Francium - Fr. In honor of the country of France.

Thus, 15 elements glorify and keep in their names the memory of the great cities and countries of our Earth.

Names of planets in elements

The cosmos has always excited the minds and made them wonder and think about what it is. Many magical properties were attributed to him. His objects became names for existing chemical elements. Examples of such atoms:

neptunium;
plutonium;
uranus;
tellurium;
selenium;
helium.

Thus, the Sun, Moon, Earth and other planets were reflected in the names.

Mythology in names

Many elements are named after mythical heroes, gods, and creatures. Examples include:

titanium (in honor of the titans children);
cobalt and nickel (in honor of evil spirits);
vanadium (goddess Vanadis);
niobium (princess niobe);
promethium (in honor of Prometheus);
tantalum (mythical king Tantalus);
thorium (god Thor).

Mythical stories, legends have always been passed from mouth to mouth. Now many of them will not be forgotten, as their heroes are reflected in the names of chemical elements.

Color palette of names

Atoms are also named according to the color of the visible part of the spectrum during spectrometric or chromatographic analysis of the composition of its simple substance. For example, phosphorus was named for its ability to "wear light", that is, it glows with white light. also some others:

sulfur - "yellow";
chlorine - "greenish";
rubidium - "dark red";
indium - "indigo", a beautiful bright blue;
tin - "white";
antimony - "black", hair dye;
iodine - "purple";
cesium - "grayish blue";
praseodymium - "green twin";
thallium - "green branch, shoot";
gold - "shine".

Obviously, each atom has its own history of the origin of the name, but they are all interesting, beautiful, reflect the essence of the atom itself or its discoverer.