Application of chemistry knowledge in space science. The prevalence of chemical elements on earth and in space

What is the most abundant substance in the Universe? Let's approach this issue logically. It seems to be known that this is hydrogen. Hydrogen H makes up 74% of the mass of matter in the Universe.

Let’s not go into the wilds of the unknown here, we won’t count Dark Matter and Dark Energy, we’ll only talk about ordinary matter, about the usual chemical elements located in (at the moment) 118 cells of the periodic table.

Hydrogen as it is

Atomic hydrogen H 1 is what all stars in galaxies are made of, this is the bulk of our familiar matter, which scientists call baryonic. Baryonic matter consists of ordinary protons, neutrons and electrons and is synonymous with the word substance.

But monatomic hydrogen is not exactly a chemical substance in our native, earthly understanding. This is a chemical element. And by substance we usually mean some kind of chemical compound, i.e. combination of chemical elements. It is clear that the simplest chemical substance is a compound of hydrogen with hydrogen, i.e. ordinary hydrogen gas H 2, which we know and love and with which we fill zeppelin airships, from which they then explode beautifully.

Dihydrogen H2 fills most gas clouds and nebulae in space. When, under the influence of their own gravity, they gather into stars, the rising temperature breaks the chemical bond, turning it into atomic hydrogen H 1, and the ever-increasing temperature removes the electron e- from a hydrogen atom, turning into a hydrogen ion or just a proton p+ . In stars, all matter is in the form of such ions, which form the fourth state of matter - plasma.

Again, the chemical hydrogen is not a very interesting thing, it is too simple, let's look for something more complex. Compounds made up of different chemical elements.

The next most abundant chemical element in the Universe is helium. He, it is 24% of the total mass in the Universe. In theory, the most common complex chemical substance should be a compound of hydrogen and helium, but the trouble is, helium - inert gas. Under ordinary and even not very ordinary conditions, helium will not combine with other substances or with itself. Through cunning tricks it can be forced to enter into chemical reactions, but such compounds are rare and usually do not last long.

This means we need to look for hydrogen compounds with the next most common chemical elements.
They account for only 2% of the mass of the Universe, when 98% is made up of the aforementioned hydrogen and helium.

The third most widely used product is not lithium. Li, as it might seem, looking at the periodic table. The next most abundant element in the universe is oxygen. O, which we all know, love and breathe in the form of a colorless and odorless diatomic gas, O 2. The amount of oxygen in space far outstrips all other elements from the 2% that remained minus hydrogen and helium, in fact half of the remainder, i.e. approximately 1%.

This means that the most common substance in the Universe turns out to be (we derived this postulate logically, but this is also confirmed by experimental observations) the most ordinary water H2O.

There is more water (mostly frozen in the form of ice) in the Universe than anything else. Minus hydrogen and helium, of course.

Everything is made of water, literally everything. Our Solar System also consists of water. Well, in the sense that the Sun, of course, consists mainly of hydrogen and helium, and giant gas planets like Jupiter and Saturn are assembled from them. But all the rest of the matter in the Solar System is not concentrated in rock-like planets with a metal core like Earth or Mars, or in a rocky asteroid belt. The bulk of the Solar System is in the icy debris left over from its formation; comets, most of the asteroids of the second belt (Kuiper belt) and the Oort cloud, located even further, are made of ice.

For example, the famous former planet Pluto (now dwarf planet Pluto) consists of 4/5 parts ice.

It is clear that if water is far from the Sun or any star, it freezes and turns into ice. And if too close, it evaporates, becoming water vapor, which is carried away by the solar wind (a stream of charged particles emitted by the Sun) to distant regions of the star system, where it freezes and again turns into ice.

But around any star (I repeat, around any star!) there is a zone where this water (which, again, is the most common substance in the Universe) is in the liquid phase of water itself.

The habitable zone around a star, surrounded by zones that are too hot and too cold.

There is a hell of a lot of liquid water in the Universe. Around any of the 100 billion stars in our Milky Way galaxy there are zones called Habitability Zone, in which liquid water exists, if there are planets there, and they should be there, if not at every star, then at every third, or even every tenth.

I'll say more. Ice can melt not only from the light of a star. In our Solar System, there are a lot of satellite moons orbiting gas giants, where it is too cold from a lack of sunlight, but which are affected by the powerful tidal forces of the corresponding planets. It has been proven that liquid water exists on Saturn’s moon Enceladus, it is assumed that it exists on Jupiter’s moons Europa and Ganymede, and probably many other places.

Water geysers on Enceladus captured by the Cassini probe

Even on Mars, scientists suggest that liquid water may exist in underground lakes and caverns.

Do you think I’m now going to start talking about the fact that since water is the most common substance in the Universe, that means hello to other forms of life, hello to aliens? No, just the opposite. I find it funny when I hear the statements of some overly enthusiastic astrophysicists - “look for water, you will find life.” Or - “there is water on Enceladus/Europa/Ganymede, which means there must probably be life there.” Or - an exoplanet located in the habitable zone was discovered in the Gliese 581 system. There is water there, we urgently equip an expedition in search of life!”

There is a lot of water in the Universe. But life, according to modern scientific data, is still somehow not very good.

In 1806, at the height of the Napoleonic Wars, an unusual meteorite fell near the French town of Alais. This was only three years after the meteorites were officially "Recognized" by the Paris Academy of Sciences. Prejudices against the “Heavenly Stones” remained very strong; some of the fragments of the Ale meteorite were simply lost, and only one of them, 28 years later, ended up in the laboratory of the famous Swedish chemist Jens Jakob Berzelius

At first, the scientist thought that a mistake had occurred - the Ale meteorite was neither stone, nor iron, nor ironstone. The melting crust (surface layer), however, testified to the cosmic origin of the unusual stone, the ancestor of the rarest and then unknown type of meteorite - carbonaceous chondrites.

The Ale meteorite contained an organic mass that was soluble in water. When heated, its particles turned brown and charred - a clear sign of the presence of organic compounds, carbon compounds. (We recall that such simple carbon-containing compounds as co, co 2, carbonic acid H 2 co 3 and its salts are inorganic compounds.) Although the similarity with terrestrial substances of the same type was obvious, Berzelius reasonably noted that this fact "is not yet Proof of the Presence of Organisms in the Original Source."

Berzelius's work marked the beginning of the study of organic compounds in meteorites. Unfortunately, the material available for research is still very rare. Carbonaceous chondrites are very fragile - they can easily be ground into powder even with your fingers (and at the same time, we repeat, a characteristic smell of oil appears. Generally rare among meteorites, carbonaceous chondrites are also easily destroyed when flying in the earth's atmosphere. And once they reach the earth's surface, they , as a rule, disappear without a trace, mixed with terrestrial rocks.It is not surprising, therefore, that only two dozen carbonaceous chondrites have been found and preserved throughout the world.

Four years after Berzelius's work was published, in 1838 another carbonaceous chondrite fell in South Africa, which was then studied by the famous German chemist Friedrich Wöhler - the same Wöhler who, several years earlier, managed to obtain a substance of animal origin - urea - from inorganic matter.

Wöhler isolated from the meteorite a petroleum-like oily substance “with a Strong Bituminous Odor” and, unlike Berzelius, came to the conclusion that such substances, “based on the current level of knowledge,” can only be synthesized by living organisms. Note that the amount of organic material released from carbonaceous hopprites is small - about one percent. But this is quite enough to draw very important conclusions.

In 1864, again in France, near the village of Or-Geil, a meteorite shower of carbonaceous chondrites fell - an exceptional case in the history of astronomy. The French chemist Kletz strictly proved that the water-insoluble black substance of the Orgueil meteorite is organic compounds, and not graphite or amorphous carbon. He was struck by the similarity of these organic compounds with similar substances found in peat or brown coal. In a report presented to the Paris Academy of Sciences, Kletz argued that organic matter in meteorites "Apparently May Indicate the Existence of Organized Matter on Celestial Bodies."

Since then, for almost a century, the study of the organics of meteorites has been carried out sporadically, from case to case, without any significant generalizations. Among these few works, mention should be made of the studies of the Migea meteorite, carried out in 1889 by Yu. Simashko. The Russian scientist also discovered organic substances of the bituminous type in this carbonaceous chondrite.

Photo of carbonaceous chondrite.
One should not think that all organic substances are necessarily associated with life or, moreover, that they belong to living beings. Astronomers know of numerous simple carbon-containing formations that certainly have no direct relation to life. These are, say, the CH and CN radicals observed in interstellar space and the atmospheres of cold stars. Moreover, in space conditions, the synthesis of very complex organic compounds, up to and including amino acids, seems to be constantly taking place. We are convinced of this, in particular, by the curious experiments of the American researcher R. Berger. Using a particle accelerator, he bombarded a mixture of methane, ammonia and water, cooled to -230 C, with protons. after just a few minutes, the scientist discovered urea, acetamide, and acetone in this icy mixture. In these experiments, Berger essentially simulated the conditions of interplanetary space. The flow of protons imitated primary cosmic rays, and the mixture of methane-ammonia and ordinary ices is, in essence, a typical model of a cometary nucleus.

Another famous American biochemist, M. Calvin, bombarded a mixture of hydrogen, methane, ammonia and water vapor with a stream of fast electrons. In these experiments, adenine was obtained - one of the four nitrogenous bases that make up nucleic acids. Didn't similar processes take place in the primary atmosphere of the earth and some other planets?

It seems that in space, protein-like compounds are created from inorganic substances and inorganically - “Semi-finished products” of a possible future life.

Thus, the presence of organic substances in meteorites in itself cannot in any way indicate the existence of life on celestial bodies. These substances could also have arisen abiogenically, without any direct connection with life. To prove the opposite, more compelling arguments are needed.

It is in this regard that the discussion in modern science about meteorites is taking place. The debate is not over yet, but the results obtained are of great interest.

Back in 1951-1952. The English biochemist Müller isolated bituminous compounds from carbonaceous chondrinth. In essence, he repeated the work of Berzelius, Wöhler and Kletz, but at an incomparably higher level. Meteorite bitumen contains much more sulfur, chlorine and nitrogen than similar terrestrial compounds; this circumstance prompted Muller to conclude that the bitumen in meteorites is of abiogenic origin.

The already mentioned M. Calvin and S. approached the same problem from a different perspective. out. The report they presented in 1960 at the international symposium on the study of outer space was significantly entitled: “extraterrestrial life. Some organic components of meteorites and their significance for possible biological evolution outside the earth.” American researchers isolated volatile substances from carbonaceous chondrite samples, which were then passed through a mass spectrometer. In these experiments, the relative mass of fragments of unknown molecules was determined and, in addition, the infrared and ultraviolet spectra of extracts of carbon-containing compounds of the meteorite were studied. The results were stunning.

From carbonaceous chondrite it was possible to isolate a substance that is exactly like cytosine - another of the four nitrogenous bases. They also found in the meteorite a mixture of hydrocarbons similar to oil of terrestrial origin.

The following year, 1961, the work of three American chemists - G. Nagy, D. Hennessey and W. - was animatedly discussed at the New York Academy of Sciences. maintaina. From carbonaceous chondrites they isolated a set of paraffins, very similar to those that are part of the skin of apples or beeswax. In this regard, disputes around the problem of the origin of oil have intensified.

We still don’t know exactly where oil came from - a source of fuel for airplanes, ships and cars, and a valuable raw material for petrochemicals. Was oil formed as a result of the decomposition of organisms that once lived, or is “Black Gold” a product of some complex abiogenic synthesis? If the first hypothesis is correct, bitumen in meteorites can be considered as traces of extraterrestrial life. Only if the oil is of inorganic origin, then meteorite bitumens have no direct relation to life outside the earth, but, apparently, arose as a result of abiogenic processes.

We have already talked about experiments simulating the formation of organic compounds in interplanetary space conditions. It is even easier to imagine such abiogenic synthesis in the depths of an Earth-like planet. Organic substances in meteorites arose abiogenically - this is the main thesis of those who do not consider meteorites to be carriers of the remains of some extraterrestrial organisms. This position is defended by Anders, Briggs, and in our Soviet Union, the researcher of carbonaceous chondrites G.P. Vdovykin. In his opinion, “the study of the spectra of various celestial bodies shows that carbon is one of the most common elements in them: it is found in the form of an element (c 2, c 3) and in the form of compounds (CH 2, CN, co 2, etc. .) In all types of celestial bodies, these components of atmospheres and stellar space could polymerize to form complex organic molecules" (L. Kuznetsova. Thirteen mysteries of the sky. M., Soviet Russia, 1967 light.

The most lively discussions are now around the mysterious “Organized Elements are coming.” These strange inclusions with a diameter of 5 to 50 microns were first discovered in 1961 by N. Nagy and D. Klaus while studying samples of four carbonaceous chondrites. Outwardly, they resembled terrestrial fossil microscopic algae. Among them, American researchers identified five types of objects based on morphological characteristics, and some of the objects turned out to be paired, as if they had died in the process of cell division. Almost all of the "Organized Elements" resembled simple plants living only in water, and this circumstance, according to Nagy and Klaus, excluded the possibility of contamination of the meteorite from the soil. Later, F. Staplin and others discovered "Organized Elements" in a number of carbonaceous chondrites, and all researchers noted their similarity to certain unicellular algae.

In 1962, Leningrad geologist b. V. Timofeev identified strange spore-like formations from the Saratov and Migei meteorites. There were more than two dozen of them - yellowish-gray, tiny, hollow, almost spherical shells, ranging from 10 to 60 microns in diameter. The shells turned out to be single-layered, varying in thickness, sometimes crumpled into clearly defined folds. According to the researcher, “the surface of the shells is smooth, less often finely tuberculate. One of the forms shows a round hole - a stomata, characteristic of some unicellular algae. Many of these finds can be compared with the oldest fossil unicellular algae on earth, which lived more than 600 million years ago. ago, but they cannot be attributed to any group of the plant world of our planet" (Ogonyok, 1962, number 4, p. 12.

Nucleic acids

Nucleic acids

Deoxyribonucleic and ribonucleic acids, universal components of all living organisms, responsible for the storage, transmission and reproduction (implementation) of genetic information. All N. to. are divided into two types according to the carbohydrate component of the molecules: deoxyribose in deoxyribonucleic acids (DNA) and ribose in ribonucleic acids (RNA). The biological role of DNA in most organisms is to store and reproduce genetic information, and RNA is to implement this information in the structure of protein molecules (proteins) during their synthesis.

Nucleic acids were discovered in 1868 by the Swiss scientist F. Miescher, who established that these substances are localized in the nuclei of cells, have acidic properties and, unlike proteins, contain phosphorus. Chemically, N.K. are polynucleotides, i.e. biopolymers built from monomer units - mononucleotides, or nucleotides (phosphorus esters of so-called nucleosides - derivatives of purine and pyrimidine nitrogenous bases, D-ribose or 2-deoxy-D-ribose). The purine bases included in the DNA molecule are adenine (A) and guanine (G), and the pyrimidine bases are cytosine (C) and thymine (T). RNA nucleosides contain uracil (U) instead of thymine. Nucleotides are connected into a polynucleotide chain through a phosphodiester bond (Fig. 1).

The primary structure of nitrogenous bases is determined by the order of alternation of nitrogenous bases, and their spatial configuration is determined by non-covalent interactions between sections of the molecule: hydrogen bonds between nitrogenous bases, hydrophobic interactions between the planes of base pairs, electrostatic interactions involving negatively charged phosphate groups and counterions.

Deoxyribonucleic acids isolated from various organisms differ in the ratio of their constituent nitrogenous bases, i.e. according to the nucleotide composition, which in all DNA obeys Chargaff’s rule: 1) the number of adenine molecules in a NK molecule is equal to the number of thymine molecules, i.e. A = T; 2) the number of guanine molecules is equal to the number of cytosine molecules, i.e. G = C; 3) the number of molecules of purine bases is equal to the number of molecules of pyrimidine bases; 4) the number of 6-amino groups is equal to the number of 6-keto groups, which means that the sum of adenine + cytosine is equal to the sum of guanine + thymine, i.e. A + C = G + T. Chargaff's rule is also valid for the so-called minor nitrogenous bases (methylated or other derivatives of purine and pyrimidine bases). Thus, the nucleotide composition of each DNA is characterized by a constant value - the molar ratio

(specificity factor) or percentage of G-C pairs, i.e.

The value of the last indicator is almost the same for organisms of the same class. In higher plants and vertebrates it is 0.55-0.93.

A study published in the journal Nature showed that organic compounds with unexpectedly high levels of complexity exist throughout the universe. The findings suggest that complex organic compounds may be created by stars.

Professor Sun Kuok and Dr Yong Zhang from the University of Hong Kong have demonstrated that organic substances in the universe are composed of both aromatic (cyclic form) and aliphatic (chain) compounds. These compounds are so complex that their chemical structure resembles coal or oil. Since coal and oil are remnants of ancient life, this form of organic matter was thought to be formed exclusively from living organisms. The team's discovery suggests that complex organic compounds can be synthesized in space even in the absence of any life forms.

Scientists have been investigating a mysterious phenomenon: a pattern of infrared radiation in stars, interstellar space and galaxies. Their spectral signatures are known as "unidentified infrared emissions." For more than two decades, the most widely accepted theory about the origin of these signatures was that they were simple organic molecules made of carbon and hydrogen atoms called polycyclic aromatic hydrocarbons (PAHs). Using observations from the Infrared Space Observatory and the Spitzer Space Telescope, Kuok and Zhang demonstrated that the emission spectrum could not be explained by the presence of PAH molecules. The team hypothesized that the substances that generate such infrared radiation have a much more complex chemical structure.

Stars not only create this complex organic matter, but also push it into interstellar space. The findings are consistent with an earlier idea proposed by Kuok that old stars are molecular factories capable of making organic mixtures. "Our work demonstrates that stars can easily create complex organic compounds in near-vacuum conditions," Kuok said. "Theoretically this is impossible, but we can nevertheless see it."

Even more interesting is the fact that the structure of this organic stardust is similar to complex organic compounds that are found in meteorites. Since meteorites are remnants of the early Solar System, the question arises whether stars could have enriched the early Solar System with organic compounds. The question of what role these compounds played in the process of the origin and development of life on Earth remains open.

“Carbon occurs in nature both in free and combined states, in very different forms and types. In the free state, carbon is known in at least three forms: coal, graphite and diamond. In the state of compounds, carbon is part of the so-called organic substances, i.e., many substances found in the body of every plant and animal. It is found in the form of carbon dioxide in water and air, and in the form of carbon dioxide salts and organic residues in the soil and the mass of the earth's crust. The variety of substances that make up the body of animals and plants is known to everyone. Wax and oil, turpentine and resin, cotton paper and protein, plant cell tissue and animal muscle tissue, tartaric acid and starch - all these and many other substances included in the tissues and juices of plants and animals are carbon compounds. The area of ​​carbon compounds is so large that it constitutes a special branch of chemistry, that is, the chemistry of carbon or, better, hydrocarbon compounds.”

These words from D.I. Mendeleev’s “Fundamentals of Chemistry” serve as a kind of extended epigraph to our story about the vital element - carbon. However, there is one thesis here, which, from the point of view of modern science of matter, can be argued with, but more on that below.

There are probably enough fingers to count the chemical elements that have not been covered in at least one scientific book. But an independent popular science book - not some brochure on 20 incomplete pages with a cover made of wrapping paper, but a completely solid volume of almost 500 pages - contains only one element - carbon.

In general, the literature on carbon is very rich. These are, firstly, all books and articles by organic chemists without exception; secondly, almost everything related to polymers; thirdly, countless publications related to fossil fuels; fourthly, a significant part of the biomedical literature...

Therefore, we will not try to embrace the immensity (after all, it is no coincidence that the authors of the popular book about element No. 6 called it “Inexhaustible”!, but we will focus only on the main thing of the main thing - we will try to see carbon from three points of view.

Carbon is one of the few elements “without clan, without tribe.” The history of human interaction with this substance goes back to prehistoric times. The name of the discoverer of carbon is unknown, and it is also unknown which form of elemental carbon - diamond or graphite - was discovered first. Both happened too long ago. Only one thing can be said with certainty: before diamond and before graphite, a substance was discovered that just a few decades ago was considered the third, amorphous form of elemental carbon - coal. But in reality, charcoal, even charcoal, is not pure carbon. It contains hydrogen, oxygen, and traces of other elements. True, they can be removed, but even then the carbon in coal will not become an independent modification of elemental carbon. This was established only in the second quarter of our century. Structural analysis showed that amorphous carbon is essentially the same as graphite. This means that it is not amorphous, but crystalline; only its crystals are very small and have more defects. After this, they began to believe that carbon on Earth exists only in two elementary forms - in the form of graphite and diamond.

Video Organic compounds in space

Alkanes. Structure and nomenclature

By definition, alkanes are saturated or saturated hydrocarbons that have a linear or branched structure. Also called paraffins. Alkane molecules contain only single covalent bonds between carbon atoms. General formula –

To name a substance, you must follow the rules. According to international nomenclature, names are formed using the suffix -an. The names of the first four alkanes were formed historically. Starting from the fifth representative, the names are composed of a prefix indicating the number of carbon atoms and the suffix -an. For example, okta (eight) forms octane.

For branched chains, the names are added up:

• from numbers indicating the numbers of carbon atoms near which the radicals are located;
• from the name of radicals;
• from the name of the main circuit.

Example: 4-methylpropane – the fourth carbon atom in the propane chain has a radical (methyl).

Rice. 1. Structural formulas with the names of alkanes.

Every tenth alkane gives the name to the next nine alkanes. After the decan come undecane, dodecane and then, after eicosane - heneicosane, docosane, tricosane, etc.

Organic and inorganic substances. Organic matter

Organic compounds differ from inorganic ones primarily in their composition. If inorganic substances can be formed by any elements of the Periodic Table, then organic substances must certainly include C and H atoms. Such compounds are called hydrocarbons (CH4 - methane, C6H6 - benzene). Hydrocarbon raw materials (oil and gas) bring enormous benefits to humanity. However, it also causes serious discord.

Hydrocarbon derivatives also contain O and N atoms. Representatives of oxygen-containing organic compounds are alcohols and their isomeric ethers (C2H5OH and CH3-O-CH3), aldehydes and their isomers - ketones (CH3CH2CHO and CH3COCH3), carboxylic acids and complex ethers (CH3-COOH and HCOOCH3). The latter also include fats and waxes. Carbohydrates are also oxygen-containing compounds.

Why did scientists combine plant and animal substances into one group - organic compounds and how do they differ from inorganic ones? There is no single clear criterion to separate organic and inorganic substances. Let us consider a number of characteristics that unite organic compounds.

1. Composition (built from atoms C, H, O, N, less often P and S).
2. Structure (C-H and C-C bonds are required, they form chains and cycles of different lengths);
3. Properties (all organic compounds are flammable, forming CO2 and H2O during combustion).

Among organic substances there are many polymers of natural (proteins, polysaccharides, natural rubber, etc.), artificial (viscose) and synthetic (plastics, synthetic rubbers, polyester, etc.) origin. They have a large molecular weight and a more complex structure compared to inorganic substances.

Finally, there are more than 25 million organic substances.

This is just a superficial look at organic and inorganic substances. More than a dozen scientific works, articles and textbooks have been written about each of these groups.

As we have already indicated above, the living matter of the considered shell of the Earth is considered to be the entire set of organisms belonging to all kingdoms of nature. People occupy a special position among all. The reasons for this were:

• a consumer position, not a producing one;
• development of mind and consciousness.

All other representatives are living matter. The functions of living matter were developed and indicated by Vernadsky. He assigned the following role to organisms:

1. Redox.
2. Destructive.
3. Transport.
4. Environment-forming.
5. Gas.
6. Energy.
7. Informational.
8. Concentration.

The most basic functions of living matter in the biosphere are gas, energy and redox. However, the rest are also important, ensuring complex processes of interaction between all parts and elements of the living shell of the planet.

Let's look at each of the functions in more detail to understand what exactly is meant and what the essence is.

Nature has generously scattered its material resources throughout our planet. But it is not difficult to notice the dependence: most often a person uses those substances whose raw material reserves are limited, and, conversely, he very poorly uses such chemical elements and their compounds, the raw material resources of which are almost limitless. In fact, 98.6% of the mass of the physically accessible layer of the Earth consists of just eight chemical elements: iron (4.6%), oxygen (47%), silicon (27.5%), magnesium (2.1%), aluminum (8.8%), calcium (3.6%), sodium (2.6%), potassium (2.5%), nickel. More than 95% of all metal products, structures of a wide variety of machines and mechanisms, and transport routes are made from iron ore raw materials. It is clear that such a practice is wasteful from the point of view of both the depletion of iron resources and the energy costs for the primary processing of iron ore raw materials.

Looking at the data presented here on the prevalence of the eight named chemical elements, we can safely say that there are great opportunities in using aluminum, and then magnesium and perhaps calcium in the creation of metal materials of the near future, but for this to happen, energy-efficient methods for producing aluminum must be developed in order to obtaining aluminum chloride and reducing the latter to metal. This method has already been tested in a number of countries and provided the basis for the design of high-capacity aluminum smelters. But aluminum smelting on a scale comparable to the production of cast iron, steel and ferroalloys cannot yet be realized in the very near future, because this task must be solved in parallel with the development of corresponding aluminum alloys capable of competing with cast iron, steel and other materials from iron ore raw materials .

The widespread occurrence of silicon serves as a constant reproach to humanity in the sense of the extremely low degree of use of this chemical element in the production of materials. Silicates make up 97% of the total mass of the earth's crust. And this gives grounds to assert that they should be the main raw materials for the production of almost all building materials and semi-finished products in the manufacture of ceramics that can compete with metals. In addition, it is necessary to take into account the huge accumulations of industrial waste of a silicate nature, such as “waste rock” from coal mining, “tailings” from the extraction of metals from ores, ash and slag from energy and metallurgical production. And it is precisely these silicates that must first be converted into raw materials for building materials. On the one hand, this promises great benefits, since raw materials do not need to be mined, they are ready-made and await their consumer. On the other hand, its disposal is a measure to combat environmental pollution.

In space, only two elements are most widely distributed - hydrogen and helium; all other elements can only be considered as an addition to them.

Question 54. Development of ideas about the chemical structure of matter. Chemical compounds.

Chemistry is the science of chemical elements and their compounds.

The history of the development of chemical concepts begins in ancient times. Democritus and Epicurus expressed brilliant thoughts that all bodies consist of atoms of different sizes and different shapes, which determines their qualitative difference. Aristotle and Empedocles believed that bodies combine

The first truly effective method for determining the properties of a substance was proposed in the second half of the 17th century. English scientist R. Boyle (1627-1691). The results of experimental research by R. Boyle showed that the qualities and properties of bodies depend on what material elements they consist of .

In 1860, the outstanding Russian chemist A.M. Butlerov (1828-1886) created a theory of the chemical structure of matter - a higher level of development of chemical knowledge arose - structural chemistry.

During this period, the technology of organic substances was born.

Under the influence of new production requirements, the doctrine of chemical processes arose , which took into account the change in the properties of a substance under the influence of temperature, pressure, solvents and other factors replacing wood and metal in construction work, food raw materials in the production of drying oil, varnishes, detergents and lubricants.

In 1960-1970 the next, higher level of chemical knowledge appeared - evolutionary chemistry . It is based on the principle of self-organization of chemical systems, that is, the principle of applying the chemical experience of highly organized living nature.

Until recently, chemists considered it clear what should be classified as chemical compounds and what should be classified as mixtures. Back in 1800-1808. French scientist J. Proust (1754-1826) established the law of constancy of composition: any individual chemical compound has a strictly defined, unchanging composition, a strong attraction of its constituent parts (atoms) and thus differs from mixtures

Since the end of the 19th century. Research was resumed that questioned the absolutization of the law of constancy of composition. The outstanding Russian chemist N.S. Kurnakov (1860-1941), as a result of studies of intermetallic compounds, i.e. compounds consisting of two metals, established the formation of real individual compounds of variable composition and found the limits of their homogeneity on the “composition-property” diagram, separating from them the regions of existence of compounds of stoichiometric composition. He called chemical compounds of variable composition berthollides, and left the name for compounds of constant composition colorblind people.

As the results of physical research have shown, the essence of the problem of chemical compounds lies not so much in the constancy or inconstancy of the chemical composition, but in the physical nature of the chemical bonds that unite atoms into a single quantum mechanical system - a molecule.

The number of chemical compounds is enormous. They differ in both composition and chemical and physical properties. But still chemical compound - a qualitatively defined substance consisting of one or more chemical elements.

While “hot” nuclear processes in space - the plasma state, nucleogenesis (the process of elements) inside stars, etc. - are mainly dealt with by physics. - a new field of knowledge that received significant development in the 2nd half of the 20th century. mainly due to the successes of astronautics. Previously, studies of chemical processes in outer space and the composition of cosmic bodies were carried out mainly through radiation from the Sun, stars and, partly, the outer layers of planets. This method allowed the element to be discovered on the Sun before it was discovered on Earth. The only direct method for studying cosmic bodies was the phase composition of various meteorites that fell on Earth. Thus, significant material was accumulated, which is of fundamental importance for further development. The development of astronautics, flights of automatic stations to the planets of the solar system - the Moon, Venus, Mars - and, finally, man's visit to the Moon opened up completely new opportunities. First of all, this is a direct study of the Moon with the participation of astronauts or by taking samples by automatic (mobile and stationary) devices and delivering them to Earth for further study in chemical laboratories. In addition, automatic descent vehicles made it possible to study the conditions of its existence in and on the surface of other planets of the Solar System, primarily Mars and Venus. One of the most important tasks is the study of the composition and abundance of cosmic bodies, the desire to explain on a chemical basis their origin and history. The greatest attention is paid to the problems of prevalence and distribution. The prevalence in space is determined by nucleogenesis within stars. The chemical composition of the Sun, the terrestrial planets of the solar system and meteorites is apparently almost identical. The formation of nuclei is associated with various nuclear processes in stars. Therefore, at different stages of their life, different stars and stellar systems have different chemical compositions. There are known stars with particularly strong spectral lines of Ba or Mg or Li, etc. The phase distribution in cosmic processes is extremely diverse. The state of aggregation and phase in space at different stages of its transformations is influenced in many ways: 1) a huge range, from stellar to absolute zero; 2) a huge range, from millions in the conditions of planets and stars to space; 3) deeply penetrating galactic and solar radiation of varying composition and intensity; 4) radiation accompanying the transformation of unstable into stable; 5) magnetic, gravitational, etc. physical fields. It has been established that all these factors influence the composition of the outer crust of the planets, their gas shells, meteorite, cosmic, etc. Moreover, the processes of fractionation in space concern not only the atomic, but also the isotopic composition. Determining isotopes that arose under the influence of radiation allows us to deeply penetrate into the history of the processes of formation of planets, asteroids, meteorites and establish the age of these processes. Due to extreme conditions in outer space, processes occur and states that are not characteristic of Earth occur: the plasma state of stars (for example, the Sun); condensation of He, Na, CH 4, NH 3 and other highly volatile substances in large planets at very low temperatures; formation of stainless steel in space on the Moon; chondritic structure of stony meteorites; the formation of complex organics in meteorites and, probably, on the surface of planets (for example, Mars). In interstellar space, they are found in extremely small and many elements, as well as (, etc.) and, finally, there is a synthesis of various complex ones (arising from the primary solar H, CO, NH 3, O 2, N 2, S and other simple compounds in equilibrium conditions with the participation of radiation). All these organic substances in meteorites and in interstellar space are not optically active.

With the development of astrophysics and some other sciences, the possibilities for obtaining information related to. Thus, searches in the interstellar medium are carried out using radio astronomy methods. By the end of 1972, more than 20 species were discovered in interstellar space, including several rather complex organic ones, containing up to 7. It has been established that the observed ones are 10-100 million times less than. These methods also make it possible, by comparing radio lines of isotopic varieties of one (for example, H 2 12 CO and H 2 13 CO), to study the isotopic composition of the interstellar and verify the correctness of existing theories of origin.

Of exceptional importance for the knowledge of space is the study of the complex multi-stage process of low-temperature, for example, the transition of solar to solid planets of the solar system, asteroids, meteorites, accompanied by condensation growth, accretion (increase in mass, “growth” of any by adding particles from the outside, for example from a gas-dust cloud) and agglomeration primary aggregates (phases) with simultaneous loss of volatiles into outer space. In space, at relatively low temperatures (5000-10000 °C), solid phases of different chemical compositions (depending on) sequentially fall out of the cooling phase, characterized by different binding energies, oxidation potentials, etc. For example, in chondrites there are silicate, metallic, sulfide, chromite, phosphide, carbide and other phases, which agglomerate at some point in their history into a stony meteorite and, probably, in a similar way into terrestrial planets.

Next, in the planets there is a process of differentiation of solid, cooling into shells - a metal core, silicate phases (mantle and crust) and - as a result of the secondary heating of the planets by heat of radiogenic origin, released during the decay of radioactive, and, possibly, other elements. This process of melting during volcanism is characteristic of the Moon, Earth, Mars, and Venus. It is based on the universal principle of the zone, separating the fusible (for example, the crust and) from the refractory mantle of planets. For example, primary solar CaSiO 3 + CO 2 reaches an equilibrium state in which it contains 97% CO 2 at 90 atm. The example of the Moon suggests that secondary (volcanic) ones are not retained by a celestial body if its mass is small.

Collisions in outer space (either between meteorite particles, or during the impact of meteorites and other particles on the surface of planets), due to the enormous cosmic velocities, can cause thermal heat, leaving traces in the structure of solid cosmic bodies, and the formation of meteorite craters. Happens between cosmic bodies. For example, according to a minimum estimate, at least 1 × to others, and in the general case - to a change in isotopic or atomic composition,” 1971, c. eleven; Aller L.H., trans. from English, M., 1963; Seaborg G. T., Valens E. G., Elements of the Universe, trans. from English, 2nd ed., M., 1966; Merrill P. W., Space chemistry, Ann Arbor, 1963; Spitzer L., Diffuse matter in space, N. Y., 1968; Snyder L. E., Buhl D., Molecules in the interstellar medium, “Sky and Telescope”, 1970, v. 40, p. 267, 345.

Cosmochemistry (from Space and Chemistry

the science of the chemical composition of cosmic bodies, the laws of abundance and distribution of chemical elements in the Universe, the processes of combination and migration of atoms during the formation of cosmic matter. The most studied part of K. - Geochemistry , K. studies primarily “cold” processes at the level of atomic-molecular interactions of substances, while “hot” nuclear processes in space—the plasma state of matter, nucleogenesis (the process of formation of chemical elements) inside stars, etc.—are primarily studied by physics. K. is a new field of knowledge that received significant development in the 2nd half of the 20th century. mainly due to the successes of astronautics. Previously, studies of chemical processes in outer space and the composition of cosmic bodies were carried out mainly through spectral analysis (See Spectral analysis) of radiation from the Sun, stars, and, partly, the outer layers of planetary atmospheres. This method allowed the element helium to be discovered on the Sun before it was discovered on Earth. The only direct method for studying cosmic bodies was the analysis of the chemical and phase composition of various meteorites that fell on Earth. Thus, significant material was accumulated, which was of fundamental importance for the further development of space exploration. The development of astronautics, flights of automatic stations to the planets of the solar system - the Moon, Venus, Mars - and, finally, man’s visit to the Moon opened up completely new opportunities for space exploration. First of all, this is a direct study of lunar rocks with the participation of astronauts or by taking soil samples by automatic (mobile and stationary) devices and delivering them to Earth for further study in chemical laboratories. In addition, automatic descent vehicles made it possible to study matter and the conditions of its existence in the atmosphere and on the surface of other planets of the Solar System, primarily Mars and Venus. One of the most important tasks of calculus is the study of the evolution of cosmic bodies on the basis of the composition and abundance of chemical elements, the desire to explain on a chemical basis their origin and history. The greatest attention in calculus is given to the problems of the prevalence and distribution of chemical elements. The abundance of chemical elements in space is determined by nucleogenesis within stars. The chemical composition of the Sun, the terrestrial planets of the solar system and meteorites is apparently almost identical. The formation of nuclei of chemical elements is associated with various nuclear processes in stars. Therefore, at different stages of their evolution, different stars and stellar systems have different chemical compositions. There are known stars with particularly strong spectral lines of Ba or Mg or Li, etc. The distribution of chemical elements among phases in cosmic processes is extremely diverse. The aggregate and phase state of matter in space at different stages of its transformations is influenced in many ways: 1) a huge range of temperatures, from stellar temperatures to absolute zero; 2) a huge range of pressures, from millions of atmospheres in the conditions of planets and stars to the vacuum of space; 3) deeply penetrating galactic and solar radiation of varying composition and intensity; 4) radiation accompanying the transformation of unstable atoms into stable ones; 5) magnetic, gravitational and other physical fields. It has been established that all these factors influence the composition of the substance of the outer crust of the planets, their gas shells, meteorite matter, cosmic dust, etc. Moreover, the processes of fractionation of matter in space concern not only the atomic, but also the isotopic composition. Determining isotopic equilibria that arose under the influence of radiation makes it possible to penetrate deeply into the history of the processes of formation of the substance of planets, asteroids, and meteorites and to determine the age of these processes. Due to extreme conditions in outer space, processes occur and states of matter that are not characteristic of Earth occur: the plasma state of the matter of stars (for example, the Sun); condensation of He, Na, CH 4, NH 3 and other highly volatile gases in the atmosphere of large planets at very low temperatures; the formation of stainless iron in the vacuum of space during explosions on the Moon; chondritic structure of the substance of stony meteorites; the formation of complex organic substances in meteorites and, probably, on the surface of planets (for example, Mars). In interstellar space, atoms and molecules of many elements are found in extremely small concentrations, as well as minerals (quartz, silicates, graphite, etc.) and, finally, there is a synthesis of various complex organic compounds (arising from the primary solar gases H, CO, NH 3, O 2, N 2, S and other simple compounds in equilibrium conditions with the participation of radiation). All these organic substances in meteorites and in interstellar space are not optically active.

With the development of astrophysics (See Astrophysics) and some other sciences, the possibilities for obtaining information related to space have expanded. Thus, the search for molecules in the interstellar medium is carried out using the methods of radio astronomy (See Radio astronomy). By the end of 1972, more than 20 types of molecules were discovered in interstellar space, including several rather complex organic molecules containing up to 7 atoms. It has been established that their observed concentrations are 10-100 million times less than the concentration of hydrogen. These methods also make it possible, by comparing radio lines of isotopic varieties of one molecule (for example, H 2 12 CO and H 2 13 CO), to study the isotopic composition of interstellar gas and test the correctness of existing theories of the origin of chemical elements.

Of exceptional importance for understanding the chemistry of space is the study of the complex multi-stage process of condensation of low-temperature plasma matter, for example, the transition of solar matter into solid matter of planets of the Solar System, asteroids, meteorites, accompanied by condensation growth, accretion (increase in mass, “growth” of any substance by adding particles from the outside, for example, from a gas and dust cloud) and agglomeration of primary aggregates (phases) with the simultaneous loss of volatile substances in the vacuum of outer space. In the vacuum of space, at relatively low temperatures (5000-10000 °C), solid phases of different chemical compositions (depending on temperature), characterized by different binding energies, oxidation potentials, etc., sequentially fall out of the cooling plasma. For example, in Chondrites silicate, metallic, sulfide, chromite, phosphide, carbide and other phases are distinguished, which agglomerate at some point in their history into a stony meteorite and, probably, in a similar way into the substance of terrestrial planets.

Further, in the planets, the process of differentiation of solid, cooling matter into shells occurs - a metal core, silicate phases (mantle and crust) and atmosphere - as a result of secondary heating of the planetary substance with heat of radiogenic origin, released during the decay of radioactive isotopes of potassium, uranium and thorium and, possibly , other elements. This process of melting and degassing of matter during volcanism is characteristic of the Moon, Earth, Mars, and Venus. It is based on the universal principle of zone melting, which separates low-melting matter (for example, the crust and atmosphere) from the refractory matter of the mantle of planets. For example, the primary solar substance has a ratio of Si/Mg≈1, the substance of the planetary crust melted from the mantle of planets has a ratio of Si/Mg≈6.5. The safety and nature of the outer shells of the planets primarily depend on the mass of the planets and their distance from the Sun (for example, the low-power atmosphere of Mars and the powerful atmosphere of Venus). Due to the proximity of Venus to the Sun, a “greenhouse” effect arose from CO 2 in its atmosphere: at temperatures above 300 ° C in the atmosphere of Venus, the process CaCO 3 + SiO 2 → CaSiO 3 + CO 2 reaches an equilibrium state at which it contains 97% CO 2 at pressure 90 atm. The example of the Moon suggests that secondary (volcanic) gases are not retained by a celestial body if its mass is small.

Collisions in outer space (either between particles of meteorite matter, or during the impact of meteorites and other particles on the surface of planets), due to the enormous cosmic velocities, can cause a thermal explosion, leaving traces in the structure of solid cosmic bodies, and the formation of meteorite craters. There is an exchange of matter between cosmic bodies. For example, according to a minimum estimate, at least 1․10 4 falls on Earth annually. T cosmic dust, the composition of which is known. Among the stone meteorites falling to the Earth, there are so-called. basaltic achondrites , composition close to the surface rocks of the Moon and terrestrial basalts (Si/Mg ≈ 6.5). In this regard, a hypothesis arose that their source is the Moon (surface rocks of its crust).

These and other processes in space are accompanied by irradiation of matter (galactic and solar radiation of high energies) at numerous stages of its transformation, which leads, in particular, to the transformation of some isotopes into others, and in the general case, to a change in the isotopic or atomic composition of matter. The longer and more diverse the processes in which the matter was involved, the further it is in chemical composition from the primary stellar (solar) composition. At the same time, the isotopic composition of cosmic matter (for example, meteorites) makes it possible to determine the composition, intensity and modulation of galactic radiation in the past.

The results of research in the field of carbon are published in the journals Geochimica et Cosmochimica Acta (N.Y., since 1950) and Geochemistry (since 1956).

Lit.: Vinogradov A.P., High-temperature protoplanetary processes, “Geochemistry”, 1971, c. eleven; Aller L.H., Prevalence of chemical elements, trans. from English, M., 1963; Seaborg G. T., Valens E. G., Elements of the Universe, trans. from English, 2nd ed., M., 1966; Merrill P. W., Space chemistry, Ann Arbor, 1963; Spitzer L., Diffuse matter in space, N. Y., 1968; Snyder L. E., Buhl D., Molecules in the interstellar medium, “Sky and Telescope”, 1970, v. 40, p. 267, 345.

A. P. Vinogradov.

Great Soviet Encyclopedia. - M.: Soviet Encyclopedia. 1969-1978 .

See what “Cosmochemistry” is in other dictionaries:

Cosmochemistry… Spelling dictionary-reference book

He studies the chemical composition of cosmic bodies, the laws of abundance and distribution of elements in the Universe, the evolution of the isotopic composition of elements, the combination and migration of atoms during the formation of cosmic matter. Research of chemical... ... Big Encyclopedic Dictionary

Noun, number of synonyms: 1 chemistry (43) ASIS Dictionary of Synonyms. V.N. Trishin. 2013… Synonym dictionary

The science that studies the prevalence and distribution of chemicals. elements in space: outer space, meteorites, stars, planets in general and their individual parts. Geological Dictionary: in 2 volumes. M.: Nedra. Edited by K. N. Paffengoltz and ... Geological encyclopedia

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Chemical science composition of the space bodies, laws of abundance and distribution of elements in the Universe, processes of combination and migration of atoms during the formation of cosmic. in va. The formation and development of K. are primarily associated with the works of V. M. Goldshmidt, G ... Chemical encyclopedia

He studies the chemical composition of cosmic bodies, the laws of abundance and distribution of elements in the Universe, the evolution of the isotopic composition of elements, the combination and migration of atoms during the formation of cosmic matter. Research of chemical... ... encyclopedic Dictionary

cosmochemistry- kosmoso chemija statusas T sritis chemija apibrėžtis Mokslas, tiriantis cheminę kosmoso objektų sudėtį. atitikmenys: engl. cosmic chemistry rus. cosmochemistry... Chemijos terminų aiškinamasis žodynas

- (from space and chemistry) the science of chemistry. composition of the space bodies, laws of prevalence and distribution of chemicals. elements in the Universe, about the synthesis of chemical nuclei. elements and changes in the isotopic composition of elements, about the processes of migration and interaction of atoms during ... Big Encyclopedic Polytechnic Dictionary