What is chemistry? Chemistry of s-elements What is chemistry as a subject.

Chemistry of s-elements.

Typical representatives, application.

Akhmetdinova Yu., Gataullina O., Solodovnikov A.

General characteristics of elements of IA and IIA groups

Group IA includes lithium, sodium, potassium, rubidium and cesium. These elements are called alkaline elements. The same group includes the artificially obtained little-studied radioactive (unstable) element francium. Sometimes hydrogen is also included in group IA. Thus, this group includes elements from each of the 7 periods.

Group IIA includes beryllium, magnesium, calcium, strontium, barium and radium. The last four elements have a group name - alkaline earth elements.

Four of these thirteen elements are most abundant in the earth's crust: Na ( w=2.63%), K ( w= 2.41%), Mg ( w= 1.95%) and Ca ( w= 3.38%). The rest are much less common, and francium is not found at all.

The orbital radii of the atoms of these elements (except hydrogen) vary from 1.04 A (for beryllium) to 2.52 A (for cesium), that is, for all atoms they exceed 1 angstrom. This leads to the fact that all of these elements are true metal forming elements, and beryllium is an amphoteric metal forming element. The general valence electronic formula of group IA elements is ns 1, and group IIA elements – ns 2 .

The large sizes of atoms and the small number of valence electrons lead to the fact that the atoms of these elements (except beryllium) tend to give up their valence electrons. The atoms of group IA elements give up their valence electrons most easily, while singly charged cations are formed from atoms of alkaline elements, and doubly charged cations are formed from atoms of alkaline earth elements and magnesium. The oxidation state in compounds of alkaline elements is +1, and that of group IIA elements is +2.

The simple substances formed by the atoms of these elements are metals. Lithium, sodium, potassium, rubidium, cesium and francium are called alkali metals because their hydroxides are alkalis. Calcium, strontium and barium are called alkaline earth metals. The chemical activity of these substances increases as the atomic radius increases.

Of the chemical properties of these metals, the most important are their reducing properties. Alkali metals are the strongest reducing agents. Metals of Group IIA elements are also quite strong reducing agents.

More details about the properties of individual s-elements can be found in the database

CHEMISTRY

a science that studies the structure of substances and their transformations, accompanied by changes in composition and (or) structure. Chem. holy things (their transformations; see Chemical reactions) are determined by ch. arr. external condition electronic shells of atoms and molecules forming substances; state of nuclei and internal electrons in chemistry processes remain almost unchanged. Chemical object research are chemical elements and their combinations, i.e. atoms, simple (single-element) and complex (molecules, radical ions, carbenes, free radicals) chemical. compounds, their combinations (associates, solvates, etc.), materials, etc. Number of chemicals. conn. huge and growing all the time; since X itself creates its object; to the end 20th century known approx. 10 million chemical connections.
X. as a science and industry does not exist for long (about 400 years). However, chem. knowledge and chemistry practice (as a craft) can be traced back thousands of years, and in a primitive form they appeared together with Homo sapiens in the process of his interaction. with the environment. Therefore, a strict definition of X. can be based on a broad, timeless, universal meaning - as a field of natural science and human practice associated with chemistry. elements and their combinations.
The word "chemistry" comes either from the name of Ancient Egypt "Hem" ("dark", "black" - apparently, from the color of the soil in the Nile River valley; the meaning of the name is "Egyptian science"), or from the ancient Greek. Chemeia - the art of smelting metals. Modern name X. is derived from Late Lat. chimia and is international, e.g. German Chemie, French chimie, English chemistry The term "X." first used in the 5th century. Greek alchemist Zosima.

History of chemistry. As an experiential practice, Xing arose with the beginnings of human society (the use of fire, cooking, tanning hides) and, in the form of crafts, early achieved sophistication (the production of paints and enamels, poisons and medicines). In the beginning, people used chemicals. changes in biol. objects (, rotting), and with the complete mastery of fire and combustion - chemical. sintering and fusion processes (pottery and glass production), metal smelting. The composition of ancient Egyptian glass (4 thousand years BC) does not differ significantly from the composition of modern glass. bottle glass. In Egypt already 3 thousand years BC. e. smelted in large quantities using coal as a reducing agent (native copper has been used since time immemorial). According to cuneiform sources, developed production of iron, copper, silver and lead existed in Mesopotamia also 3 thousand years BC. e. Mastering chemistry the processes of producing copper and, and then iron, were stages in the evolution of not only metallurgy, but civilization as a whole, changing the living conditions of people, influencing their aspirations.
At the same time, theoretical theories arose. generalizations. For example, Chinese manuscripts from the 12th century. BC e. report "theoretical" building systems of “basic elements” (fire, wood, and earth); In Mesopotamia, the idea of ​​rows of pairs of opposites, interaction, was born. which “make up the world”: male and female, heat and cold, moisture and dryness, etc. The idea (of astrological origin) of the unity of the phenomena of macrocosm and microcosm was very important.
Conceptual values ​​also include atomistic values. a doctrine that was developed in the 5th century. BC e. Ancient Greek philosophers Leucippus and Democritus. They proposed analog semantic. a model of the structure of a thing, which has a deep combinatorial meaning: combinations, according to certain rules, of a small number of indivisible elements (atoms and letters) into compounds (molecules and words) create information wealth and diversity (of things and languages).
In the 4th century. BC e. Aristotle created chem. a system based on the “principles”: dryness - and cold - heat, with the help of pairwise combinations of which in “primary matter” he derived 4 basic elements (earth, water and fire). This system existed almost unchanged for 2 thousand years.
After Aristotle, leadership in chemistry. knowledge gradually passed from Athens to Alexandria. Since that time, recipes for obtaining chemicals have been created. in-institutions arise (like the temple of Serapis in Alexandria, Egypt), engaged in activities that the Arabs would later call “al-chemistry”.
In the 4th-5th centuries. chem. knowledge penetrates into Asia Minor (together with Nestorianism), philosophical schools arise in Syria, translating the Greek. natural philosophy and transmitted chemistry. knowledge to the Arabs.
In the 3rd-4th centuries. arose alchemy - a philosophical and cultural movement that combines mysticism and magic with craft and art. Alchemy brought it in. contribution to the lab. skill and technique, obtaining many pure chemicals. in-in. Alchemists supplemented Aristotle's elements with 4 principles (oil, moisture, and sulfur); combinations of these mystical elements and principles determined the individuality of each island. Alchemy had a noticeable influence on the formation of Western European culture (the combination of rationalism with mysticism, knowledge with creation, the specific cult of gold), but did not spread in other cultural regions.
Jabir ibn Hayyan, or in European Geber, Ibn Sina (Avicenna), Abu ar-Razi and other alchemists introduced chemistry. everyday life (from urine), gunpowder, pl. , NaOH, HNO3. Geber's books, translated into Latin, enjoyed enormous popularity. From the 12th century Arabic alchemy begins to lose practicality. direction, and with it leadership. Penetrating through Spain and Sicily into Europe, it stimulates the work of European alchemists, the most famous of whom were R. Bacon and R. Lull. From the 16th century practical development is developing. European alchemy, stimulated by the needs of metallurgy (G. Agricola) and medicine (T. Paracelsus). The latter founded the pharmacological branch of chemistry - iatrochemistry, and together with Agricola, he actually acted as the first reformer of alchemy.
X. as a science arose during the scientific revolution of the 16th and 17th centuries, when a new civilization arose in Western Europe as a result of a series of closely related revolutions: religious (Reformation), which gave a new interpretation of the godliness of earthly affairs; scientific, which gave a new, mechanistic. picture of the world (heliocentrism, infinity, subordination to natural laws, description in the language of mathematics); industrial (the emergence of the factory as a system of machines using fossil energy); social (destruction of feudal and formation of bourgeois society).
X., following the physics of G. Galileo and I. Newton, could become a science only along the path of mechanism, which set the basic norms and ideals of science. In X. it was much more difficult than in physics. Mechanics is easily abstracted from the characteristics of an individual object. In X. each private object (in-in) is an individuality, qualitatively different from others. X. could not express its subject purely quantitatively and throughout its history remained a bridge between the world of quantity and the world of quality. However, the hopes of anti-mechanists (from D. Diderot to W. Ostwald) that X. will lay the foundations of a different, non-mechanistic. sciences did not materialize, and X. developed within the framework defined by Newton’s picture of the world.
For more than two centuries X. developed an idea of ​​the material nature of its object. R. Boyle, who laid the foundations of rationalism and experimentation. method in X., in his work “The Skeptical Chemist” (1661) developed ideas about chemistry. atoms (corpuscles), differences in the shape and mass of which explain the qualities of individual substances. Atomistic ideas in X. were reinforced ideologically. the role of atomism in European culture: man-atom is a model of man, which forms the basis of a new social philosophy.
Metallurgical X., which dealt with the processes of combustion, oxidation and reduction, calcination - calcination of metals (X. was called pyrotechnics, that is, fiery art) - drew attention to the gases formed during this process. J. van Helmont, who introduced the concept of "gas" and discovered it (1620), laid the foundation for pneumatics. chemistry. Boyle in his work “Fire and Flame Weighed on Balances” (1672), repeating the experiments of J. Rey (1630) on increasing the mass of metal during firing, came to the conclusion that this occurs due to “the capture of weighty particles of flame by the metal.” On the border of the 16th-17th centuries. G. Stahl formulates the general theory of X. - the theory of phlogiston (caloric, i.e., the “flammability substance” removed with the help of air from substances during their combustion), which freed X. from lasting 2 thousand years Aristotle's systems. Although M.V. Lomonosov, having repeated the firing experiments, discovered the law of conservation of mass in chemistry. p-tions (1748) and was able to give a correct explanation of the processes of combustion and oxidation as an interaction. in-va with air particles (1756), the knowledge of combustion and oxidation was impossible without the development of pneumatic. chemistry. In 1754 J. Black (re)discovered carbon dioxide ("fixed air"); J. Priestley (1774) - , G. Cavendish (1766) - ("flammable air"). These discoveries provided all the information necessary to explain the processes of combustion, oxidation and respiration, which is what A. Lavoisier did in the 1770-90s, thereby effectively burying the theory of phlogiston and gaining the fame of “the father of modern X.”
To the beginning 19th century pneumatochemistry and studies of the composition of substances have brought chemists closer to understanding that chemistry. elements are combined in certain, equivalent ratios; the laws of constancy of composition (J. Proust, 1799-1806) and volumetric relations (J. Gay-Luc-sac, 1808) were formulated. Finally, J. Dalton, Most. fully outlined his concept in the essay “New System of Chemical Philosophy” (1808-27), convinced his contemporaries of the existence of atoms, introduced the concept of atomic weight (mass) and brought back to life the concept of an element, but in a completely different sense - as a collection of atoms of the same type .
The hypothesis of A. Avogadro (1811, accepted by the scientific community under the influence of S. Cannizzaro in 1860) that the particles of simple gases are molecules of two identical atoms, resolved a number of contradictions. Picture of the material nature of chemistry. the facility was completed with the opening of periodic. chemical law elements (D.I. Mendeleev, 1869). He linked the quantities. measure () with quality (chemical properties), revealed the meaning of the concept of chemical. element, gave the chemist a theory of great predictive power. X. became modern. science. Periodic the law legitimized X.’s own place in the system of sciences, resolving the latent conflict of chemistry. reality with the norms of mechanism.
At the same time, there was a search for the causes and forces of chemicals. interactions. Dualism has emerged. (electrochemical) theory (I. Berzelius, 1812-19); the concepts "" and "chemical bond" were introduced, which were filled with physical meaning with the development of the theory of atomic structure and quantum X. They were preceded by intensive research into org. in-in the 1st half. 19th century, which led to the division of X. into 3 parts: inorganic chemistry, organic chemistry And analytical chemistry(until the 1st half of the 19th century, the latter was the main section of X.). New empiric. the material (substitution solutions) did not fit into Berzelius’s theory, so ideas were introduced about groups of atoms acting in solutions as a whole - radicals (F. Wöhler, J. Liebig, 1832). These ideas were developed by C. Gerard (1853) into the theory of types (4 types), the value of which was that it was easily associated with the concept of valency (E. Frankland, 1852).
In the 1st half. 19th century one of the most important phenomena of X was discovered. catalysis(the term itself was proposed by Berzelius in 1835), which very soon found widespread practical use. application. All R. 19th century Along with important discoveries of such new substances (and classes), as dyes (V. Perkin, 1856), concepts important for the further development of X. were put forward. In 1857-58, F. Kekule developed the theory of valence as applied to org. v-you, established the tetravalency of carbon and the ability of its atoms to bond with each other. This paved the way for the theory of chemistry. structures of org. conn. (structural theory), built by A. M. Butlerov (1861). In 1865 Kekule explained the nature of aromatics. conn. J. van't Hoff and J. Le Bel, postulating tetrahedral. structures (1874), paved the way for a three-dimensional view of the structure of the island, laying the foundations stereochemistry as an important section of X.
All R. 19th century At the same time, research in the field of chemical kinetics And thermochemistry. L. Wilhelmy studied the kinetics of hydrolysis of carbohydrates (for the first time giving an equation for the rate of hydrolysis; 1850), and K. Guldberg and P. Waage formulated the law of mass action in 1864-67. G. I. Hess discovered the fundamental law of thermochemistry in 1840, M. Berthelot and V. F. Luginin studied the heats of many. districts. At the same time, work on colloid chemistry, photochemistry And electrochemistry, Crimea began back in the 18th century.
The works of J. Gibbs, Van't Hoff, V. Nernst and others are creating chemical Studies of the electrical conductivity of solutions and electrolysis led to the discovery of electrolytic. dissociation (S. Arrhenius, 1887). In the same year, Ostwald and Van't Hoff founded the first magazine dedicated to physical chemistry, and it took shape as an independent discipline. K ser. 19th century it is customary to attribute the origin agrochemistry And biochemistry, especially in connection with Liebig's pioneering work (1840s) on enzymes, proteins and carbohydrates.
19th century by right m.b. called the century of chemical discoveries. elements. During these 100 years, more than half (50) of the elements existing on Earth were discovered. For comparison: in the 20th century. 6 elements were discovered, in the 18th century - 18, before the 18th century - 14.
Outstanding discoveries in physics at the end. 19th century (X-rays, electron) and the development of theoretical. ideas (quantum theory) led to the discovery of new (radioactive) elements and the phenomenon of isotopy, the emergence radiochemistry And quantum chemistry, new ideas about the structure of the atom and the nature of chemistry. connections, giving rise to the development of modern X. (chemistry of the 20th century).
Successes of the X. 20th century. associated with the progress of the analyte. X. and physical methods for studying substances and influencing them, penetration into the mechanisms of processes, with the synthesis of new classes of substances and new materials, differentiation of chemicals. disciplines and integration of X. with other sciences, meeting the needs of modern times. industry, engineering and technology, medicine, construction, agriculture and other spheres of human activity in new chemicals. knowledge, processes and products. Successful application of new physical methods of influence led to the formation of new important directions of X., for example. radiation chemistry, plasma chemistry. Together with X. low temperatures ( cryochemistry) and X. high pressures (see. Pressure), sonochemistry (see Ultrasound), laser chemistry etc. they began to form a new area - X. extreme impacts, which plays a large role in obtaining new materials (for example, for electronics) or old valuable materials with relatively cheap synthetic materials. by (eg diamonds or metal nitrides).
One of the first places in X. is given to the problems of predicting the functional properties of an item based on knowledge of its structure and determining the structure of an item (and its synthesis) based on its functional purpose. The solution to these problems is associated with the development of quantum chemical calculations. methods and new theoretical approaches, with success in non-org. and org. synthesis. Work on genetic engineering and the synthesis of compounds is being developed. with unusual structure and properties (for example, high-temperature superconductors). Methods based on matrix synthesis, and also using ideas planar technology. Methods that simulate biochemistry are being further developed. districts. Advances in spectroscopy (including scanning tunneling) have opened up prospects for the “design” of substances at the pier. level, led to the creation of a new direction in X. - the so-called. nanotechnology. To control chemical processes both in the laboratory and in industry. scale, the principles are beginning to be used. and prayer. organizing ensembles of reacting molecules (including approaches based on thermodynamics of hierarchical systems).
Chemistry as a knowledge system about substances and their transformations. This knowledge is contained in a stock of facts - reliably established and verified information about chemistry. elements and compounds, their conditions and behavior in natural and arts. environments Criteria for the reliability of facts and methods for their systematization are constantly evolving. Large generalizations that reliably connect large sets of facts become scientific laws, the formulation of which opens new stages of X. (for example, the laws of conservation of mass and energy, Dalton’s laws, Mendeleev’s periodic law). Theories using specific concepts, explain and predict facts of a more specific subject area. In fact, experimental knowledge becomes a fact only when it receives theoretical knowledge. interpretation. So, the first chem. theory - the theory of phlogiston, although incorrect, contributed to the formation of X., because it connected facts into a system and made it possible to formulate new questions. Structural theory (Butlerov, Kekule) organized and explained a huge amount of organizational material. X. and determined the rapid development of chemistry. synthesis and study of the structure of org. connections.
X. as knowledge is a very dynamic system. The evolutionary accumulation of knowledge is interrupted by revolutions - a deep restructuring of the system of facts, theories and methods, with the emergence of a new set of concepts or even a new style of thinking. Thus, the revolution was caused by the works of Lavoisier (materialistic theory of oxidation, the introduction of quantitative experimental methods, the development of chemical nomenclature), the discovery of periodic. Mendeleev's law, creation in the beginning. 20th century new analytes methods (microanalysis, ). The emergence of new areas that develop a new vision of the subject of X and influence all its areas (for example, the emergence of physical X on the basis of chemical thermodynamics and chemical kinetics) can also be considered a revolution.
Chem. knowledge has a developed structure. The framework of X. consists of basic chemicals. disciplines that developed in the 19th century: analytical, non-org., org. and physical X. Subsequently, during the evolution of the structure of A., a large number of new disciplines were formed (for example, crystal chemistry), as well as a new engineering branch - chemical Technology.
A large set of research areas grows on the framework of disciplines, some of which are included in one or another discipline (for example, X. elemental organic compound - part of org. X.), others are multidisciplinary in nature, i.e. require unification into one study by scientists from different disciplines (for example, studying the structure of biopolymers using a complex of complex methods). Still others are interdisciplinary, that is, they require the training of a specialist in a new profile (for example, X. nerve impulse).
Since almost all practical human activity is associated with the use of matter as substances, chemicals. knowledge is necessary in all areas of science and technology that master the material world. Therefore, today X. has become, along with mathematics, a repository and generator of such knowledge, which “permeates” almost the entire rest of science. That is, highlighting X. as a set of areas of knowledge, we can also talk about chemistry. aspect of most other fields of science. There are many hybrid disciplines and fields at the "frontiers" of X.
At all stages of development as a science, X. experiences the powerful influence of physical science. sciences - first Newtonian mechanics, then thermodynamics, atomic physics and quantum mechanics. Atomic physics provides knowledge that is part of the foundation of X., reveals the meaning of periodicity. law, helps to understand the patterns of prevalence and distribution of chemicals. elements in the Universe, which is the subject of nuclear astrophysics and cosmochemistry.
Fundam. X. was influenced by thermodynamics, which sets fundamental restrictions on the possibility of chemical reactions. r-tions (chemical thermodynamics). X., whose entire world was originally associated with fire, quickly mastered thermodynamics. way of thinking. Van't Hoff and Arrhenius connected the study of the speed of reactions (kinetics) -X with thermodynamics. received modern way to study the process. Study of chemistry kinetics required the involvement of many private physical scientists. disciplines to understand the processes of substance transfer (see, for example, Diffusion, Mass transfer Expansion and deepening of mathematization (for example, the use of math. modeling, graph theory) allows us to talk about the formation of mat. X. (it was predicted by Lomonosov, calling one of his books “Elements of Mathematical Chemistry”).

The language of chemistry. Information system. Subject X. - elements and their compounds, chemical. interaction of these objects - has a huge and rapidly growing diversity. The language of L. is correspondingly complex and dynamic. Its dictionary includes the name. elements, compounds, chemicals. particles and materials, as well as concepts reflecting the structure of objects and their interaction. The language of X. has a developed morphology - a system of prefixes, suffixes and endings that make it possible to express the qualitative diversity of chemistry. world with great flexibility (see Chemical nomenclature). The X. dictionary has been translated into the language of symbols (signs, ph-l, ur-nium), which make it possible to replace the text with a very compact expression or visual image (for example, spatial models). The creation of the scientific language of X. and a method of recording information (primarily on paper) is one of the great intellectual feats of European science. The international community of chemists has managed to establish constructive worldwide work in such a controversial matter as the development of terminology, classification and nomenclature. A balance was found between everyday language, historical (trivial) chemical names. compounds and their strict formula designations. The creation of the X. language is an amazing example of a combination of very high mobility and progress with stability and continuity (conservatism). Modern chem. The language allows a huge amount of information to be recorded very briefly and unambiguously and exchanged between chemists around the world. Machine-readable versions of this language have been created. The diversity of the X. object and the complexity of the language make the X. information system the most. large and sophisticated in all science. It is based on chemical journals, as well as monographs, textbooks, reference books. Thanks to the tradition of international coordination that arose early in X., more than a century ago, standards for the description of chemistry were formed. in-in and chem. districts and the beginning of a system of periodically updated indexes was laid (for example, the index of the Beilstein org. connection; see also Chemical reference books and encyclopedias). Huge scale of chemical literature already 100 years ago prompted us to look for ways to “compress” it. Abstract journals (RJ) emerged; After the 2nd World War, two maximally complete Russian Journals were published in the world: “Chemical Abstracts” and “RJ Chemistry”. Automation systems are being developed on the basis of RZh. information retrieval systems.

Chemistry as a social system- the largest part of the entire community of scientists. The formation of a chemist as a type of scientist was influenced by the characteristics of the object of his science and the method of activity (chemical experiment). Difficulties mat. formalization of the object (in comparison with physics) and at the same time the variety of sensory manifestations (smell, color, biol., etc.) from the very beginning limited the dominance of mechanism in the thinking of the chemist and left it. a field for intuition and artistry. In addition, the chemist always used non-mechanical tools. nature - fire. On the other hand, in contrast to the stable, nature-given objects of a biologist, the world of a chemist has an inexhaustible and rapidly growing diversity. The irreducible mystery of the new plant imparted responsibility and caution to the chemist’s worldview (as a social type, the chemist is conservative). Chem. The laboratory has developed a strict mechanism of “natural selection”, rejecting arrogant and error-prone people. This gives originality not only to the style of thinking, but also to the spiritual and moral organization of the chemist.
The community of chemists consists of people who are professionally involved in X. and consider themselves to be in this field. About half of them work, however, in other areas, providing them with chemicals. knowledge. In addition, they are joined by many scientists and technologists - to a large extent chemists, although they no longer consider themselves chemists (mastering the skills and abilities of a chemist by scientists in other fields is difficult due to the above-mentioned features of the subject).
Like any other close-knit community, chemists have their own professional language, personnel reproduction system, communications system [magazines, congresses, etc.], their own history, their own cultural norms and style of behavior.

Research methods. Special area of ​​chemistry. knowledge - chemical methods. experiment (analysis of composition and structure, synthesis of chemical substances). A. - most pronounced experimental the science. The range of skills and techniques that a chemist must master is very wide, and the range of methods is growing rapidly. Since chemical methods experiments (especially analysis) are used in almost all areas of science, X. develops technologies for all science and combines it methodically. On the other hand, X. shows a very high sensitivity to methods born in other areas (primarily physics). Her methods are highly interdisciplinary.
In research. For X purposes, a huge range of ways to influence things is used. At first it was thermal, chemical. and biol. impact. Then high and low pressures, mech., magnetic were added. and electric influences, flows of ions of elementary particles, laser radiation, etc. Now more and more of these methods are penetrating into production technology, which opens up a new important channel for communication between science and production.

Organizations and institutions. Chem. Research is a special type of activity that has developed an appropriate system of organizations and institutions. Chemical engineering has become a special type of institution. laboratory, the device is designed to meet the basic functions performed by a team of chemists. One of the first laboratories was created by Lomonosov in 1748, 76 years earlier than the chemist. laboratories appeared in the USA. Space The structure of the laboratory and its equipment make it possible to store and use a large number of devices, instruments and materials, including potentially very dangerous and incompatible ones (flammable, explosive and toxic).
The evolution of research methods in X. led to the differentiation of laboratories and the identification of many methodologies. laboratories and even instrument centers, which specialize in servicing a large number of teams of chemists (analyses, measurements, influence on substances, calculations, etc.). An institution that unites laboratories working in similar areas with con. 19th century became researched. int (see Chemical Institutes). Very often chem. The institute has an experimental production - a semi-industrial system. installations for the production of small batches of substances and materials, their testing and development of technology. modes.
Chemists are trained in chemistry. faculties of universities or specialties. higher educational institutions, which differ from others in the large proportion of practical work and the intensive use of demonstration experiments in theoretical studies. courses. Development of chemical workshops and lecture experiments - a special genre of chemistry. research, pedagogy and, in many ways, art. Since mid. 20th century The training of chemists began to go beyond the university and cover earlier age groups. Specialists have emerged. chem. secondary schools, clubs and olympiads. In the USSR and Russia, one of the best pre-institutional chemical systems in the world was created. preparation, the genre of popular chemistry has been developed. literature.
For storage and transfer of chemicals. knowledge there is a network of publishing houses, libraries and information centers. A special type of X. institutions consists of national and international bodies for managing and coordinating all activities in this area - state and public (see, for example, International Union of Pure and Applied Chemistry).
The system of institutions and organizations of X. is a complex organism, which has been “grown” for 300 years and is considered in all countries as a great national treasure. Only two countries in the world had an integral system of organizing X. in the structure of knowledge and in the structure of functions - the USA and the USSR.

Chemistry and society. X. is a science, the range of relations between the swarm and society has always been very wide - from admiration and blind faith (“chemicalization of the entire national economy”) to equally blind denial (“nitrate” boom) and chemophobia. The image of an alchemist was transferred to X. - a magician who hides his goals and has an incomprehensible power. Poisons and gunpowder in the past, nerve paralytic. and psychotropic substances today - the common consciousness associates these instruments of power with X. Since the chemical. industry is an important and necessary component of the economy, chemophobia is often deliberately incited for opportunistic purposes (artificial environmental psychosis).
In fact, X. is a system-forming factor in modern times. society, i.e. an absolutely necessary condition for its existence and reproduction. First of all, because X. participates in the formation of modern. person. The vision of the world through the prism of concepts X cannot be removed from his worldview. Moreover, in industrial civilization, a person retains his status as a member of society (is not marginalized) only if he quickly masters new chemicals. presentation (for which a whole system of popularizing X. is used). The entire technosphere - the artificially created world around humans - is increasingly becoming saturated with chemical products. production, handling of which requires a high level of chemicals. knowledge, skills and intuition.
In con. 20th century The general inadequacy of societies is increasingly felt. institutes and everyday consciousness of industrial society to the level of modern chemicalization. peace. This discrepancy gave rise to a chain of contradictions that became a global problem and created a qualitatively new danger. At all social levels, including the scientific community as a whole, the lag in chemical levels is growing. knowledge and skills from chem. reality of the technosphere and its impact on the biosphere. Chem. education and upbringing in general schools is becoming scarce. The gap between chemical preparation of politicians and the potential danger of wrong decisions. Organization of a new, reality-appropriate system of universal chemistry. education and mastery of chemistry. culture becomes a condition for the security and sustainable development of civilization. During the crisis (which promises to be long), a reorientation of X’s priorities is inevitable: from knowledge for the sake of improving living conditions to knowledge for the sake of guarantees. preservation of life (from the criterion of “maximizing benefits” to the criterion of “minimizing damage”).

Applied chemistry. The practical, applied significance of X. is to exercise control over chemicals. processes occurring in nature and the technosphere, in the production and transformation of substances and materials needed by humans. In most industries up to the 20th century. processes inherited from the craft period dominated. X., earlier than other sciences, began to generate products, the very principle of which was based on scientific knowledge (for example, the synthesis of aniline dyes).
Chemical state industry largely determined the pace and direction of industrialization and politics. situation (such as, for example, the creation of large-scale production of ammonia and nitric acid by Germany using the Geber-Bosch method, which was not foreseen by the Entente countries, which provided it with a sufficient quantity of explosives to wage a world war). The development of the mineral industry, fertilizers, and then plant protection products sharply increased agricultural productivity, which became a condition for urbanization and rapid industrial development. Replacement of technical arts cultures. in-you and materials (fabrics, dyes, fat substitutes, etc.) means equally. increase in food supply. resources and raw materials for light industry. Condition and economic The efficiency of mechanical engineering and construction is increasingly determined by the development and production of synthetic materials. materials (plastics, rubbers, films and fibers). The development of new communication systems, which in the near future will radically change and have already begun to change the face of civilization, is determined by the development of fiber optic materials; the progress of television, computer science and computerization is associated with the development of the element base of microelectronics and piers. electronics. In general, the development of the technosphere today largely depends on the range and quantity of chemicals produced. industrial products. The quality of many chemicals products (for example, paints and varnishes) also affects the spiritual well-being of the population, that is, it participates in the formation of the highest human values.
It is impossible to overestimate the role of X. in the development of one of the most important problems facing humanity - environmental protection (see. Protection of Nature). Here, X.'s task is to develop and improve methods for detecting and determining anthropogenic pollution, studying and modeling chemistry. processes occurring in the atmosphere, hydrosphere and lithosphere, the creation of waste-free or low-waste chemicals. production, development of methods for neutralization and disposal of industrial products. and household waste.

Lit.: Fngurovsky N. A., Essay on the general history of chemistry, vol. 1-2, M., 1969-79; Kuznetsov V.I., Dialectics of the development of chemistry, M., 1973; Soloviev Yu. I., Trifonov D. N., Shamin A. N., History of chemistry. Development of the main directions of modern chemistry, M., 1978; Jua M., History of Chemistry, trans. from Italian, M., 1975; Legasov V. A., Buchachenko A. L., "Advances in Chemistry", 1986, v. 55, v. 12, p. 1949-78; Fremantle M., Chemistry in Action, trans. from English, parts 1-2, M., 1991; Pimentel J., Coonrod J., Possibilities of Chemistry Today and Tomorrow, trans. from English, M., 1992; Par ting ton J. R., A history of chemistry, v. 1-4, L.-N.Y., 1961-70. WITH.

G. Kara-Murza, T. A. Aizatulin. Dictionary of foreign words of the Russian language

CHEMISTRY- CHEMISTRY, the science of substances, their transformations, interactions and the phenomena occurring during this process. Clarification of the basic concepts with which X operates, such as atom, molecule, element, simple body, reaction, etc., the doctrine of molecular, atomic and... ... Great Medical Encyclopedia

- (possibly from the Greek Chemia Chemia, one of the most ancient names of Egypt), a science that studies the transformations of substances, accompanied by changes in their composition and (or) structure. Chemical processes (obtaining metals from ores, dyeing fabrics, dressing leather and... ... Big Encyclopedic Dictionary

CHEMISTRY, a branch of science that studies the properties, composition and structure of substances and their interaction with each other. Currently, chemistry is a broad field of knowledge and is divided primarily into organic and inorganic chemistry.... ... Scientific and technical encyclopedic dictionary

CHEMISTRY, chemistry, many others. no, female (Greek chemeia). The science of composition, structure, changes and transformations, as well as the formation of new simple and complex substances. Chemistry, says Engels, can be called the science of qualitative changes in bodies that occur... ... Ushakov's Explanatory Dictionary

chemistry- – the science of the composition, structure, properties and transformations of substances. Dictionary of analytical chemistry analytical chemistry colloidal chemistry inorganic chemistry ... Chemical terms

A set of sciences, the subject of which is the combination of atoms and the transformations of these compounds that occur with the rupture of some and the formation of other interatomic bonds. Various chemistry and sciences differ in that they deal with either different classes... ... Philosophical Encyclopedia

chemistry- CHEMISTRY, and, g. 1. Harmful production. Work in chemistry. Send for chemistry. 2. Drugs, pills, etc. 3. All unnatural, harmful products. It's not just sausage chemistry. Eat your own chemicals. 4. A variety of hairstyles with chemical... ... Dictionary of Russian argot

Science * History * Mathematics * Medicine * Discovery * Progress * Technology * Philosophy * Chemistry Chemistry He who does not understand anything other than chemistry does not understand it enough. Lichtenberg Georg (Lichtenberg) (

Lecture 10
Chemistry of s-elements
Issues covered:
1. Elements of the main subgroups of groups I and II
2. Properties of atoms of s-elements
3. Crystal lattices of metals
4. Properties of simple substances - alkaline and alkaline earth
metals
5. Prevalence of s-elements in nature
6. Obtaining SHM and SHZM
7. Properties of s-element compounds
8. Hydrogen is a special element
9. Isotopes of hydrogen. Properties of atomic hydrogen.
10. Production and properties of hydrogen. Chemical education
communications.
11. Hydrogen bond.
12. Hydrogen peroxide - structure, properties.

Sulfur is located in group VIa of the Periodic Table of Chemical Elements D.I. Mendeleev.
The outer energy level of sulfur contains 6 electrons, which have 3s 2 3p 4. In compounds with metals and hydrogen, sulfur exhibits a negative oxidation state of elements -2, in compounds with oxygen and other active non-metals - positive +2, +4, +6. Sulfur is a typical non-metal; depending on the type of transformation, it can be an oxidizing agent and a reducing agent.

Finding sulfur in nature

Sulfur is found in a free (native) state and bound form.

The most important natural sulfur compounds:

FeS 2 - iron pyrite or pyrite,

ZnS - zinc blende or sphalerite (wurtzite),

PbS - lead luster or galena,

HgS - cinnabar,

Sb 2 S 3 - stibnite.

In addition, sulfur is present in oil, natural coal, natural gases, and natural waters (in the form of sulfate ions and determines the “permanent” hardness of fresh water). A vital element for higher organisms, an integral part of many proteins, is concentrated in the hair.

Allotropic modifications of sulfur

Allotropy- this is the ability of the same element to exist in different molecular forms (molecules contain different numbers of atoms of the same element, for example, O 2 and O 3, S 2 and S 8, P 2 and P 4, etc.).

Sulfur is distinguished by its ability to form stable chains and cycles of atoms. The most stable are S8, which form orthorhombic and monoclinic sulfur. This is crystalline sulfur - a brittle yellow substance.

Open chains have plastic sulfur, a brown substance, which is obtained by sharp cooling of molten sulfur (plastic sulfur becomes brittle after a few hours, acquires a yellow color and gradually turns into rhombic).

1) rhombic - S 8

t°pl. = 113°C; r = 2.07 g/cm 3

The most stable modification.

2) monoclinic - dark yellow needles

t°pl. = 119°C; r = 1.96 g/cm 3

Stable at temperatures above 96°C; under normal conditions it turns into rhombic.

3) plastic - brown rubber-like (amorphous) mass

Unstable, when hardening it turns into a rhombic

Obtaining sulfur

1. The industrial method is smelting the ore using steam.
2. Incomplete oxidation of hydrogen sulfide (with a lack of oxygen):

2H 2 S + O 2 → 2S + 2H 2 O

1. Wackenroeder's reaction:

2H 2 S + SO 2 → 3S + 2H 2 O

Chemical properties of sulfur

Oxidative properties of sulfur
(S 0 + 2ē→ S -2 )

1) Sulfur reacts with alkaline substances without heating:

S + O 2 – t° → S +4 O 2

2S + 3O 2 – t °; pt → 2S +6 O 3

4) (except iodine):

S+Cl2 → S +2 Cl 2

S + 3F 2 → SF 6

With complex substances:

5) with acids - oxidizing agents:

S + 2H 2 SO 4 (conc) → 3S +4 O 2 + 2H 2 O

S+6HNO3(conc) → H 2 S +6 O 4 + 6NO 2 + 2H 2 O

Disproportionation reactions:

6) 3S 0 + 6KOH → K 2 S +4 O 3 + 2K 2 S -2 + 3H 2 O

7) sulfur dissolves in a concentrated solution of sodium sulfite:

S 0 + Na 2 S +4 O 3 → Na 2 S 2 O 3 sodium thiosulfate