home Tests Scientific discoveries in chemistry of the 20th century. Famous Russian chemists: list, achievements, discoveries and interesting facts. Sergei Vasilievich Lebedev

Scientific discoveries in chemistry of the 20th century. Famous Russian chemists: list, achievements, discoveries and interesting facts. Sergei Vasilievich Lebedev

Robert BOYLE

He was born on January 25, 1627 in Lismore (Ireland), and was educated at Eton College (1635-1638) and at the Geneva Academy (1639-1644). After that, he lived almost without a break at his estate in Stallbridge, where he conducted his chemical research for 12 years. In 1656 Boyle moved to Oxford, and in 1668 moved to London.

The scientific activity of Robert Boyle was based on the experimental method in both physics and chemistry, and developed the atomistic theory. In 1660, he discovered the law of change in the volume of gases (in particular, air) with a change in pressure. He later received the name Boyle-Mariotte law: independently of Boyle, this law was formulated by the French physicist Edm Mariotte.

Boyle studied a lot of chemical processes - for example, those that occur during the roasting of metals, the dry distillation of wood, the transformations of salts, acids and alkalis. In 1654 he introduced the concept of body composition analysis. One of Boyle's books was called The Skeptic Chemist. It defined elements how " primitive and simple, not completely mixed bodies, which are not composed of each other, but are those constituent parts of which all so-called mixed bodies are composed and into which the latter can finally be resolved".

And in 1661, Boyle formulates the concept of " primary corpuscles " both elements and " secondary corpuscles like complex bodies.

He was also the first to give an explanation for differences in the aggregate state of bodies. In 1660 Boyle received acetone, distilling potassium acetate, in 1663 he discovered and applied in research an acid-base indicator litmus in a litmus lichen growing in the mountains of Scotland. In 1680 he developed a new method for obtaining phosphorus made of bones phosphoric acid and phosphine...

At Oxford, Boyle took an active part in the founding of a scientific society, which in 1662 was transformed into Royal Society of London(in fact, this is the English Academy of Sciences).

Robert Boyle died on December 30, 1691, leaving future generations with a rich scientific legacy. Boyle wrote many books, some of them were published after the death of the scientist: some of the manuscripts were found in the archives of the Royal Society ...

AVOGADRO Amedeo

(1776 – 1856)

Italian physicist and chemist, member of the Turin Academy of Sciences (since 1819). Born in Turin. He graduated from the Faculty of Law of the University of Turin (1792). Since 1800, he independently studied mathematics and physics. In 1809 - 1819. taught physics at the Vercelli Lyceum. In 1820 - 1822 and 1834 - 1850. Professor of Physics at the University of Turin. Scientific works relate to various fields of physics and chemistry. In 1811, he laid the foundations of molecular theory, generalized the experimental material accumulated by that time on the composition of substances, and brought into a single system the experimental data of J. Gay-Lussac and the basic provisions of J. Dalton's atomistics that contradicted each other.

He discovered (1811) the law according to which the same volumes of gases at the same temperatures and pressures contain the same number of molecules ( Avogadro's law). named after Avogadro universal constant is the number of molecules in 1 mole of an ideal gas.

He created (1811) a method for determining molecular weights, by means of which, according to the experimental data of other researchers, he was the first to correctly calculate (1811-1820) the atomic masses of oxygen, carbon, nitrogen, chlorine and a number of other elements. Established quantitative atomic composition molecules of many substances (in particular, water, hydrogen, oxygen, nitrogen, ammonia, nitrogen oxides, chlorine, phosphorus, arsenic, antimony), for which it was previously determined incorrectly. Indicated (1814) the composition of many alkaline and alkaline earth metals, methane, ethyl alcohol, ethylene. He was the first to draw attention to the analogy in the properties of nitrogen, phosphorus, arsenic and antimony - chemical elements that later formed the VA group of the Periodic Table. The results of Avogadro's work on molecular theory were recognized only in 1860 at the First International Congress of Chemists in Karlsruhe.

In 1820-1840. studied electrochemistry, studied the thermal expansion of bodies, heat capacities and atomic volumes; at the same time, he obtained conclusions that are coordinated with the results of later studies by D.I. Mendeleev on the specific volumes of bodies and modern ideas about the structure of matter. He published the work "Physics of Weighted Bodies, or a Treatise on the General Construction of Bodies" (vols. 1-4, 1837 - 1841), in which, in particular, paths were outlined for ideas about the nonstoichiometric nature of solids and about the dependence of the properties of crystals on their geometry.

Jens Jakob Berzelius

(1779-1848)

Swedish chemist Jens Jakob Berzelius was born into the family of a school principal. The father died shortly after his birth. Jacob's mother remarried, but after the birth of her second child, she fell ill and died. The stepfather did everything to ensure that Jacob and his younger brother received a good education.

Jacob Berzelius became interested in chemistry only at the age of twenty, but already at the age of 29 he was elected a member of the Royal Swedish Academy of Sciences, and two years later - its president.

Berzelius experimentally confirmed many chemical laws known by that time. The efficiency of Berzelius is amazing: he spent 12-14 hours a day in the laboratory. During his twenty years of scientific activity, he investigated more than two thousand substances and accurately determined their composition. He discovered three new chemical elements (cerium Ce, thorium Th and selenium Se), and for the first time isolated silicon Si, titanium Ti, tantalum Ta and zirconium Zr in the free state. Berzelius did a lot of theoretical chemistry, compiled annual reviews of the progress of the physical and chemical sciences, and was the author of the most popular chemistry textbook in those years. Perhaps this was what made him introduce convenient modern designations of elements and chemical formulas into chemical use.

Berzelius married only at the age of 55 the twenty-four-year-old Johanna Elisabeth, the daughter of his old friend Poppius, the State Chancellor of Sweden. Their marriage was happy, but there were no children. In 1845, Berzelius' health deteriorated. After one particularly severe attack of gout, he was paralyzed in both legs. In August 1848, at the age of 70, Berzelius died. He is buried in a small cemetery near Stockholm.

Vladimir Ivanovich VERNADSKY

Vladimir Ivanovich Vernadsky, while studying at St. Petersburg University, listened to the lectures of D.I. Mendeleev, A.M. Butlerov and other famous Russian chemists.

Over time, he himself became a strict and attentive teacher. Almost all mineralogists and geochemists of our country are his students or students of his students.

The outstanding naturalist did not share the point of view that minerals are something immutable, part of the established "system of nature." He believed that in nature there is a gradual interconversion of minerals. Vernadsky created a new science - geochemistry. Vladimir Ivanovich was the first to note the enormous role living matter- all plant and animal organisms and microorganisms on Earth - in the history of movement, concentration and dispersion of chemical elements. The scientist drew attention to the fact that some organisms are able to accumulate iron, silicon, calcium and other chemical elements and can participate in the formation of deposits of their minerals, that microorganisms play a huge role in the destruction of rocks. Vernadsky argued that " the key to life cannot be obtained by studying the living organism alone. To resolve it, one must also turn to its primary source - to the earth's crust.".

Studying the role of living organisms in the life of our planet, Vernadsky came to the conclusion that all atmospheric oxygen is a product of the vital activity of green plants. Vladimir Ivanovich paid special attention environmental issues. He considered global environmental issues affecting the biosphere as a whole. Moreover, he created the very doctrine of biosphere- an area of active life, covering the lower part of the atmosphere, the hydrosphere and the upper part of the lithosphere, in which the activity of living organisms (including humans) is a factor on a planetary scale. He believed that the biosphere, under the influence of scientific and industrial achievements, is gradually moving into a new state - the sphere of reason, or noosphere. The decisive factor in the development of this state of the biosphere should be the rational activity of man, harmonious interaction of nature and society. This is possible only if the close relationship between the laws of nature and the laws of thought and socio-economic laws is taken into account.

John DALTON

(Dalton J.)

John Dalton was born in poor family, possessed great modesty and an extraordinary thirst for knowledge. He did not hold any important university position, he was a simple teacher of mathematics and physics at school and college.

Basic scientific research before 1800-1803. relate to physics, later - to chemistry. Conducted (since 1787) meteorological observations, investigated the color of the sky, the nature of heat, refraction and reflection of light. As a result, he created the theory of evaporation and mixing of gases. Described (1794) a visual defect called color blind.

opened three laws, which constituted the essence of his physical atomistics of gas mixtures: partial pressures gases (1801), dependencies volume of gases at constant pressure temperature(1802, independently of J.L. Gay-Lussac) and dependencies solubility gases from their partial pressures(1803). These works led him to solve the chemical problem of the relationship between the composition and structure of substances.

Put forward and substantiated (1803-1804) theory atomic structure , or chemical atomism, which explained the empirical law of the constancy of composition. Theoretically predicted and discovered (1803) law of multiple ratios: if two elements form several compounds, then the masses of one element falling on the same mass of the other are related as integers.

Compiled (1803) the first table of relative atomic masses hydrogen, nitrogen, carbon, sulfur and phosphorus, taking the atomic mass of hydrogen as a unit. Proposed (1804) chemical sign system for "simple" and "complex" atoms. Carried out (since 1808) work aimed at clarifying certain provisions and explaining the essence of atomistic theory. Author of the work "The New System of Chemical Philosophy" (1808-1810), which is world famous.

Member of many academies of sciences and scientific societies.

Svante ARRENIUS

(b. 1859)

Svante-August Arrhenius was born in the ancient Swedish city of Uppsala. In the gymnasium, he was one of the best students; it was especially easy for him to study physics and mathematics. In 1876, the young man was admitted to Uppsala University. And two years later (six months ahead of schedule) he passed the exam for the degree of candidate of philosophy. However, later he complained that the university education was conducted according to outdated schemes: for example, "one could not hear a single word about the Mendeleev system, and yet it was already more than ten years old" ...

In 1881, Arrhenius moved to Stockholm and went to work in Physics Institute Academy of Sciences. There he began to study the electrical conductivity of highly dilute aqueous solutions electrolytes. Although Svante Arrhenius is a physicist by training, he is famous for his chemical research and became one of the founders of a new science - physical chemistry. Most of all, he studied the behavior of electrolytes in solutions, as well as the study of the rate of chemical reactions. Arrhenius's work was not recognized by his compatriots for a long time, and only when his conclusions were highly appreciated in Germany and France, he was elected to the Swedish Academy of Sciences. For development theories of electrolytic dissociation Arrhenius was awarded the Nobel Prize in 1903.

Cheerful and good-natured giant Svante Arrhenius, a real "son of the Swedish countryside", has always been the soul of society, endearing himself to colleagues and just acquaintances. He was married twice; his two sons were named Olaf and Sven. He became widely known not only as a physical chemist, but also as the author of many textbooks, popular science and simply popular articles and books on geophysics, astronomy, biology and medicine.

But the path to world recognition for Arrhenius the chemist was not at all easy. The theory of electrolytic dissociation in the scientific world had very serious opponents. So, D.I. Mendeleev sharply criticized not only the very idea of Arrhenius about dissociation, but also a purely "physical" approach to understanding the nature of solutions, which does not take into account the chemical interactions between a solute and a solvent.

Subsequently, it turned out that both Arrhenius and Mendeleev were each right in their own way, and their views, complementing each other, formed the basis of a new - proton- Theories of acids and bases.

Cavendish Henry

English physicist and chemist, member of the Royal Society of London (since 1760). Born in Nice (France). Graduated from the University of Cambridge (1753). Scientific research carried out in his own laboratory.

Works in the field of chemistry relate to pneumatic (gas) chemistry, one of the founders of which he is. Singled out (1766) in its purest form carbon dioxide and hydrogen, mistaking the latter for phlogiston, established the basic composition of air as a mixture of nitrogen and oxygen. Received nitrogen oxides. By burning hydrogen, he obtained (1784) water, having determined the ratio of the volumes of the gases interacting in this reaction (100:202). The accuracy of his research was so great that, when receiving (1785) oxides of nitrogen, by passing an electric spark through humidified air, he allowed him to observe the presence of "dephlogisticated air", which is no more than 1/20 of the total volume of gases. This observation helped W. Ramsay and J. Rayleigh discover (1894) the noble gas argon. He explained his discoveries from the standpoint of the theory of phlogiston.

In the field of physics, in many cases he anticipated later discoveries. The law according to which the forces of electrical interaction are inversely proportional to the square of the distance between charges was discovered by him (1767) ten years earlier than the French physicist C. Coulomb. Experimentally established (1771) the influence of the medium on the capacitance of capacitors and determined (1771) the value of the dielectric constants of a number of substances. He determined (1798) the forces of mutual attraction of bodies under the influence of gravity and then calculated the average density of the Earth. Cavendish's work in the field of physics became known only in 1879, after the English physicist J. Maxwell published his manuscripts, which had been in the archives until that time.

The physical laboratory organized in 1871 at the University of Cambridge is named after Cavendish.

KEKULE Friedrich August

(Kekule F.A.)

German organic chemist. Born in Darmstadt. Graduated from Giessen University (1852). He listened to the lectures of J. Dumas, C. Wurtz, C. Gerapa in Paris. In 1856-1858. taught at the University of Heidelberg, in 1858-1865. - professor at the University of Ghent (Belgium), since 1865 - at the University of Bonn (in 1877-1878 - rector). Scientific interests were predominantly concentrated in the field of theoretical organic chemistry and organic synthesis. Received thioacetic acid and other sulfur compounds (1854), glycolic acid (1856). For the first time, by analogy with the type of water, he introduced (1854) the type of hydrogen sulfide. Expressed (1857) the idea of valence as an integer number of units of affinity that an atom has. Pointed to the "bibasic" (bivalent) sulfur and oxygen. Divided (1857) all elements, with the exception of carbon, into one-, two- and three-basic ones; carbon was classified as a four-basic element (simultaneously with L.V.G. Kolbe).

Put forward (1858) the position that the constitution of compounds is determined by "basicity", that is valency, elements. For the first time (1858) showed that the number of hydrogen atoms associated with n carbon atoms, equal to 2 n+ 2. Based on the theory of types, he formulated the initial provisions of the theory of valency. Considering the mechanism of double exchange reactions, he expressed the idea of a gradual weakening of the initial bonds and presented (1858) a scheme that was the first model of the activated state. Proposed (1865) a cyclical structural formula benzene, thereby spreading the theory chemical structure Butlerov on aromatic compounds. Experimental work Kekule are closely related to his theoretical research. In order to test the hypothesis of the equivalence of all six hydrogen atoms in benzene, he obtained its halogen, nitro, amino and carboxy derivatives. Carried out (1864) a cycle of transformations of acids: natural malic - bromine - optically inactive malic. He discovered (1866) the rearrangement of diazoamino- to aminoazobenzene. Synthesized triphenylmethane (1872) and anthraquinone (1878). To prove the structure of camphor, he undertook work to convert it into oxycymol, and then into thiocymol. He studied the crotonic condensation of acetaldehyde and the reaction for obtaining carboxytartronic acid. He proposed methods for the synthesis of thiophene based on diethyl sulfide and succinic anhydride.

President of the German Chemical Society (1878, 1886, 1891). One of the organizers of the I International Congress of Chemists in Karlsruhe (1860). Foreign Corresponding Member Petersburg Academy of Sciences (since 1887).

Antoine-Laurent Lavoisier

(1743-1794)

French chemist Antoine Laurent Lavoisier A lawyer by training, he was a very wealthy man. He was a member of the Farming Company, an organization of financiers that farmed state taxes. From these financial transactions, Lavoisier acquired a huge fortune. The political events that took place in France had sad consequences for Lavoisier: he was executed for working in the "General Farm" ( joint stock company tax collection). In May 1794, among other accused tax-farmers, Lavoisier appeared before a revolutionary tribunal and was sentenced to death the next day "as an instigator or accomplice in a conspiracy, seeking to promote the success of the enemies of France by extortion and illegal requisitions from the French people." On the evening of May 8, the sentence was carried out, and France lost one of its most brilliant heads ... Two years later, Lavoisier was found unfairly convicted, however, this could no longer return the remarkable scientist to France. While still studying at the Faculty of Law at the University of Paris, the future general farmer and an outstanding chemist simultaneously studied the natural sciences. Part of his fortune Lavoisier invested in the arrangement of a chemical laboratory, equipped with excellent equipment for those times, which became scientific center Paris. In his laboratory, Lavoisier conducted numerous experiments in which he determined changes in the masses of substances during their calcination and combustion.

Lavoisier was the first to show that the mass of the combustion products of sulfur and phosphorus is greater than the mass of the burned substances, and that the volume of air in which phosphorus burned decreased by 1/5 part. By heating mercury with a certain volume of air, Lavoisier obtained "mercury scale" (mercury oxide) and "suffocating air" (nitrogen), unsuitable for combustion and breathing. Calcining mercury scale, he decomposed it into mercury and "vital air" (oxygen). With these and many other experiments, Lavoisier showed the complexity of the composition atmospheric air and for the first time correctly interpreted the phenomena of combustion and roasting as the process of combining substances with oxygen. This could not be done by the English chemist and philosopher Joseph Priestley and the Swedish chemist Karl-Wilhelm Scheele, as well as other naturalists who reported the discovery of oxygen earlier. Lavoisier proved that carbon dioxide (carbon dioxide) is a combination of oxygen with "coal" (carbon), and water is a combination of oxygen with hydrogen. He experimentally showed that when breathing, oxygen is absorbed and carbon dioxide is formed, that is, the breathing process is similar to the combustion process. Moreover, the French chemist established that the formation of carbon dioxide during respiration is the main source of "animal heat". Lavoisier was one of the first to try to explain the complex physiological processes occurring in a living organism in terms of chemistry.

Lavoisier became one of the founders of classical chemistry. He discovered the law of conservation of substances, introduced the concepts of "chemical element" and "chemical compound", proved that breathing is like a combustion process and is a source of heat in the body. Lavoisier was the author of the first classification of chemicals and the textbook "Elementary Chemistry Course". At the age of 29 he was elected a full member of the Paris Academy of Sciences.

Henri-Louis LE CHATELIER
(Le Chatelier H.L.)

Henri-Louis Le Chatelier was born on October 8, 1850 in Paris. After graduating from the Polytechnic School in 1869, he entered the Higher National Mining School. The future discoverer of the famous principle was a widely educated and erudite person. He was interested in technology, natural sciences, and social life. He devoted a lot of time to the study of religion and ancient languages. At the age of 27, Le Chatelier became a professor at the Higher Mining School, and thirty years later, at the University of Paris. Then he was elected a full member of the Paris Academy of Sciences.

The most important contribution of the French scientist to science was associated with the study chemical equilibrium, research balance shift under the influence of temperature and pressure. The students of the Sorbonne, who listened to Le Chatelier's lectures in 1907-1908, wrote in their notes in the following way: " A change in any factor that can affect the state of chemical equilibrium of a system of substances causes a reaction in it that tends to counteract the change being made. An increase in temperature causes a reaction that tends to lower the temperature, that is, going with the absorption of heat. An increase in pressure causes a reaction that tends to cause a decrease in pressure, that is, accompanied by a decrease in volume...".

Unfortunately, Le Chatelier was not awarded the Nobel Prize. The reason was that this prize was awarded only to the authors of works performed or recognized in the year of receipt of the prize. The most important works of Le Chatelier were completed long before 1901, when the first Nobel Prizes were awarded.

LOMONOSOV Mikhail Vasilievich

Russian scientist, academician of the St. Petersburg Academy of Sciences (since 1745). Born in the village of Denisovka (now the village of Lomonosov, Arkhangelsk region). In 1731-1735. studied at the Slavic-Greek-Latin Academy in Moscow. In 1735 he was sent to Petersburg to an academic university, and in 1736 to Germany, where he studied at the University of Marburg (1736-1739) and in Freiberg at the School of Mining (1739-1741). In 1741-1745. - Adjunct of the Physics class of the St. Petersburg Academy of Sciences, since 1745 - professor of chemistry of the St. Petersburg Academy of Sciences, since 1748 he worked in the Chemical Laboratory of the Academy of Sciences established on his initiative. Simultaneously, from 1756, he conducted research at the glass factory he founded in Ust-Ruditsy (near St. Petersburg) and in his home laboratory.

Lomonosov's creative activity is distinguished both by the exceptional breadth of interests and the depth of penetration into the secrets of nature. His research relates to mathematics, physics, chemistry, earth sciences, astronomy. The results of these studies laid the foundations of modern natural science. Lomonosov drew attention (1756) to the fundamental importance of the law of conservation of the mass of matter in chemical reactions; outlined (1741-1750) the foundations of his corpuscular (atomic-molecular) doctrine, which was developed only a century later; put forward (1744-1748) the kinetic theory of heat; substantiated (1747-1752) the need to involve physics to explain chemical phenomena and proposed the name "physical chemistry" for the theoretical part of chemistry, and "technical chemistry" for the practical part. His works became a milestone in the development of science, delimiting natural philosophy from experimental natural science.

Until 1748, Lomonosov was engaged mainly in physical research, and in the period 1748-1757. his works are devoted mainly to the solution of theoretical and experimental problems of chemistry. Developing atomistic ideas, he was the first to express the opinion that bodies consist of "corpuscles", and those, in turn, of "elements"; it corresponds modern ideas about molecules and atoms.

He was the initiator of the application of mathematical and physical research methods in chemistry and was the first to begin teaching an independent "course of true physical chemistry" at the St. Petersburg Academy of Sciences. An extensive program was carried out in the Chemical Laboratory of the St. experimental studies. Developed accurate weighing methods, applied volumetric methods of quantitative analysis. Conducting experiments on firing metals in sealed vessels, he showed (1756) that their weight does not change after heating and that R. Boyle's opinion about the addition of thermal matter to metals is erroneous.

Studied liquid, gaseous and solid states of bodies. He determined the expansion coefficients of gases quite accurately. Studied the solubility of salts at different temperatures. Researched influence electric current on salt solutions, established the facts of a decrease in temperature during the dissolution of salts and a decrease in the freezing point of a solution compared to a pure solvent. He distinguished between the process of dissolving metals in acid, accompanied by chemical changes, and the process of dissolving salts in water, which occurs without chemical changes soluble substances. Created various instruments (viscometer, vacuum filtration device, hardness tester, gas barometer, pyrometer, boiler for the study of substances at low and high pressures), accurately calibrated thermometers.

was the creator of many chemical industries(inorganic pigments, glazes, glass, porcelain). He developed the technology and formulation of colored glass, which he used to create mosaic paintings. Invented porcelain mass. He was engaged in the analysis of ores, salts and other products.

In the work "The first foundations of metallurgy, or ore affairs" (1763), he considered the properties of various metals, gave their classification and described methods of obtaining. Along with other works on chemistry, this work laid the foundations of the Russian chemical language. Considered the formation of various minerals and non-metallic bodies in nature. He expressed the idea of the biogenic origin of soil humus. He proved the organic origin of oils, hard coal, peat and amber. He described the processes of obtaining iron sulfate, copper from copper sulfate, sulfur from sulfur ores, alum, sulfuric, nitric and hydrochloric acids.

He was the first Russian academician to start preparing textbooks on chemistry and metallurgy (Course of Physical Chemistry, 1754; The First Foundations of Metallurgy, or Mining, 1763). He is credited with the creation of Moscow University (1755), the project and training program which he personally compiled. According to his project, in 1748 the construction of the Chemical Laboratory of the St. Petersburg Academy of Sciences was completed. From 1760 he was a trustee of the gymnasium and university at the St. Petersburg Academy of Sciences. Created the foundations of modern Russian literary language. He was a poet and an artist. Wrote a number of works on history, economics, philology. Member of a number of academies of sciences. The Moscow University (1940), the Moscow Academy of Fine Chemical Technology (1940), the city of Lomonosov (former Oranienbaum) are named after Lomonosov. The Academy of Sciences of the USSR established (1956) gold medal them. M.V. Lomonosov for outstanding work in the field of chemistry and other natural sciences.

Dmitri Ivanovich Mendeleev

(1834-1907)

Dmitri Ivanovich Mendeleev- the great Russian scientist-encyclopedist, chemist, physicist, technologist, geologist and even a meteorologist. Mendeleev possessed surprisingly clear chemical thinking, he always clearly understood the ultimate goals of his creative work: foresight and benefit. He wrote: "The closest subject of chemistry is the study of homogeneous substances, from the addition of which all the bodies of the world are composed, their transformations into each other and the phenomena accompanying such transformations."

Mendeleev created the modern hydrate theory of solutions, the ideal gas equation of state, developed the technology for producing smokeless powder, discovered the Periodic Law and proposed the Periodic Table of Chemical Elements, and wrote the best chemistry textbook of its time.

He was born in 1834 in Tobolsk and was the last, seventeenth child in the family of the director of the Tobolsk gymnasium, Ivan Pavlovich Mendeleev, and his wife, Maria Dmitrievna. By the time of his birth, two brothers and five sisters survived in the Mendeleev family. Nine children died in infancy, and three of them did not even have time to give names to their parents.

The study of Dmitri Mendeleev in St. Petersburg in pedagogical institute it was not easy at first. In his first year, he managed to get unsatisfactory grades in all subjects except mathematics. But in senior years, things went differently - Mendeleev's average annual score was four and a half (out of five possible). He graduated from the institute in 1855 with a gold medal, having received a diploma of a senior teacher.

Life was not always favorable to Mendeleev: there was a break with the bride, and the malevolence of colleagues, an unsuccessful marriage and then a divorce ... Two years (1880 and 1881) were very difficult in Mendeleev's life. In December 1880, the St. Petersburg Academy of Sciences refused to elect him as an academician: nine academicians voted in favor, and ten academicians voted against. A certain Veselovsky, the secretary of the academy, played a particularly unseemly role in this. He frankly declared: "We do not want university students. If they are better than us, then we still do not need them."

In 1881, with great difficulty, Mendeleev's marriage to his first wife was annulled, who did not understand her husband at all and reproached him for his lack of attention.

In 1895, Mendeleev went blind, but continued to lead the Chamber of Weights and Measures. Business papers were read aloud to him, he dictated orders to the secretary, and blindly continued to glue the suitcases at home. Professor I.V. Kostenich removed the cataract in two operations, and soon his vision returned ...

In the winter of 1867-68, Mendeleev began to write the textbook "Fundamentals of Chemistry" and immediately encountered difficulties in systematizing the factual material. By mid-February 1869, while pondering the structure of the textbook, he gradually came to the conclusion that the properties simple substances(and this is a form of existence of chemical elements in a free state) and the atomic masses of the elements are connected by a certain regularity.

Mendeleev did not know much about the attempts of his predecessors to arrange the chemical elements in order of increasing atomic masses and about the incidents that arose in this case. For example, he had almost no information about the work of Chancourtois, Newlands, and Meyer.

Mendeleev had an unexpected idea: to compare close atomic masses of various chemical elements and their Chemical properties.

Without thinking twice, reverse side Khodnev's letters he wrote down the symbols chlorine Cl and potassium K with fairly similar atomic masses, equal to 35.5 and 39, respectively (the difference is only 3.5 units). On the same letter, Mendeleev sketched symbols of other elements, looking for similar "paradoxical" pairs among them: fluorine F and sodium Na, bromine Br and rubidium rb, iodine I and cesium Cs, for which the mass difference increases from 4.0 to 5.0, and then to 6.0. Mendeleev then could not know that the "indefinite zone" between the obvious non-metals and metals contains elements - noble gases, the discovery of which in the future will significantly modify the Periodic Table. Gradually, the appearance of the future Periodic Table of chemical elements began to take shape.

So, first he put a card with the element beryllium Be (atomic mass 14) next to the element card aluminum Al (atomic mass 27.4), according to the then tradition, taking beryllium for an analogue of aluminum. However, then, comparing the chemical properties, he placed beryllium over magnesium mg. Having doubted the then generally accepted value of the atomic mass of beryllium, he changed it to 9.4, and changed the formula of beryllium oxide from Be 2 O 3 to BeO (like magnesium oxide MgO). By the way, the "corrected" value of the atomic mass of beryllium was confirmed only ten years later. He acted just as boldly on other occasions.

Gradually, Dmitry Ivanovich came to the final conclusion that the elements, arranged in ascending order of their atomic masses, show a clear periodicity in physical and chemical properties.

Throughout the day, Mendeleev worked on the system of elements, taking short breaks to play with his daughter Olga, have lunch and dinner.

On the evening of March 1, 1869, he whitewashed the table he had compiled and, under the title "Experiment of a system of elements based on their atomic weight and chemical similarity," sent it to the printer, making notes for typesetters and putting the date "February 17, 1869" (this is according to the old style). So it was opened Periodic Law...

Chemistry of antiquity.

Chemistry, the science of the composition of substances and their transformations, begins with the discovery by man of the ability of fire to change natural materials. Apparently, people knew how to smelt copper and bronze, fire clay products, and get glass as far back as 4000 BC. By the 7th c. BC. Egypt and Mesopotamia became centers of dye production; In the same place, gold, silver and other metals were obtained in their pure form. From about 1500 to 350 BC distillation was used to produce dyes, and metals were smelted from ores by mixing them with charcoal and blowing air through the burning mixture. The very procedures for the transformation of natural materials were given a mystical meaning.

Greek natural philosophy.

These mythological ideas penetrated into Greece through Thales of Miletus, who raised the whole variety of phenomena and things to a single element - water. However, the Greek philosophers were not interested in the methods of obtaining substances and their practical use, but mainly the essence of the processes taking place in the world. Thus, the ancient Greek philosopher Anaximenes argued that the fundamental principle of the Universe is air: when rarefied, air turns into fire, and as it thickens, it becomes water, then earth and, finally, stone. Heraclitus of Ephesus tried to explain the phenomena of nature, postulating fire as the primary element.

Four primary elements.

These ideas were combined in the natural philosophy of Empedocles of Agrigent, the creator of the theory of the four principles of the universe. In various versions, his theory dominated the minds of people for more than two millennia. According to Empedocles, all material objects are formed by the combination of eternal and unchanging elements-elements - water, air, earth and fire - under the influence of the cosmic forces of love (attraction) and hatred (repulsion). The theory of the elements of Empedocles was accepted and developed first by Plato, who clarified that the immaterial forces of good and evil can turn these elements one into another, and then by Aristotle.

According to Aristotle, elements-elements are not material substances, but carriers of certain qualities - heat, cold, dryness and humidity. This view was transformed into the idea of the four "juices" of Galen and dominated science until the 17th century. Another important question that occupied the Greek natural philosophers was the question of the divisibility of matter. The founders of the concept, which later received the name "atomistic", were Leucippus, his student Democritus and Epicurus. According to their teaching, only emptiness and atoms exist - indivisible material elements, eternal, indestructible, impenetrable, differing in shape, position in emptiness and size; all bodies are formed from their "whirlwind". The atomistic theory remained unpopular for two millennia after Democritus, but did not disappear completely. One of its adherents was the ancient Greek poet Titus Lucretius Car, who outlined the views of Democritus and Epicurus in the poem On the nature of things (De Rerum Natura).

Alchemy.

Alchemy is the art of improving matter through the transformation of metals into gold and the improvement of man by creating the elixir of life. In an effort to achieve the most attractive goal for them - the creation of incalculable wealth - alchemists solved many practical problems, discovered many new processes, observed various reactions, contributing to the formation of a new science - chemistry.

Hellenistic period.

Egypt was the cradle of alchemy. The Egyptians brilliantly mastered applied chemistry, which, however, was not singled out as an independent field of knowledge, but was included in the "sacred secret art" of the priests. As a separate field of knowledge, alchemy appeared at the turn of the 2nd and 3rd centuries. AD After the death of Alexander the Great, his empire collapsed, but the influence of the Greeks spread to the vast territories of the Near and Middle East. Alchemy reached a particularly rapid flowering in 100–300 AD. in Alexandria.

Around 300 AD Egyptian Zosima wrote an encyclopedia - 28 books covering all the knowledge on alchemy for the previous 5-6 centuries, in particular information about the mutual transformations (transmutations) of substances.

Alchemy in the Arab world.

Having conquered Egypt in the 7th century, the Arabs assimilated the Greco-Oriental culture, which was preserved for centuries by the Alexandrian school. Imitating the ancient rulers, the caliphs began to patronize the sciences, and in the 7th-9th centuries. the first chemists appeared.

The most talented and famous Arab alchemist was Jabir ibn Hayyan (late 8th century), who later became known in Europe under the name Geber. Jabir believed that sulfur and mercury are two opposite principles from which seven other metals are formed; gold is the most difficult to form: this requires a special substance, which the Greeks called xerion - “dry”, and the Arabs changed it to al-iksir (this is how the word “elixir” appeared). The elixir was supposed to have other miraculous properties: to cure all diseases and give immortality. Another Arab alchemist, al-Razi (c. 865–925) (known in Europe as Razes) also practiced medicine. So, he described the method of preparing plaster and the method of applying a bandage to the fracture site. However, the most famous doctor was Ibn Sina from Bukhara, also known as Avicenna. His writings served as a guide for physicians for many centuries.

Alchemy in Western Europe.

The scientific views of the Arabs penetrated into medieval Europe in the 12th century through North Africa, Sicily and Spain. The works of Arab alchemists were translated into Latin and then into other European languages. At first, alchemy in Europe relied on the work of such luminaries as Jabir, but three centuries later there was renewed interest in the teachings of Aristotle, especially in the writings of the German philosopher and Dominican theologian, who later became a bishop and professor at the University of Paris, Albert the Great and his student Thomas Aquinas. Convinced of the compatibility of Greek and Arabic science with Christian doctrine, Albertus Magnus encouraged their introduction into scholastic curricula. In 1250 Aristotle's philosophy was introduced into the teaching curriculum at the University of Paris. The English philosopher and naturalist, Franciscan monk Roger Bacon, who anticipated many later discoveries, was also interested in alchemical problems; he studied the properties of saltpeter and many other substances, found a way to make black powder. Other European alchemists include Arnaldo da Villanova (1235-1313), Raymond Lull (1235-1313), Basil Valentine (15th-16th century German monk).

Achievements of alchemy.

The development of crafts and trade, the rise of cities in Western Europe in the 12th–13th centuries. accompanied by the development of science and the emergence of industry. Alchemists' recipes were used in technological processes such as metalworking. During these years, systematic searches for methods for obtaining and identifying new substances began. There are recipes for the production of alcohol and improvements in the process of its distillation. The most important achievement was the discovery of strong acids - sulfuric, nitric. Now European chemists were able to carry out many new reactions and obtain substances such as salts. nitric acid, vitriol, alum, salts of sulfuric and hydrochloric acids. The services of alchemists, who were often skilled doctors, were used by the highest nobility. It was also believed that alchemists possessed the secret of transmuting ordinary metals into gold.

By the end of the 14th century the interest of alchemists in the transformation of some substances into others gave way to an interest in the production of copper, brass, vinegar, olive oil and various medicines. In the 15th-16th centuries. the experience of alchemists was increasingly used in mining and medicine.

THE ORIGIN OF MODERN CHEMISTRY

The end of the Middle Ages was marked by a gradual departure from the occult, a decline in interest in alchemy, and the spread of a mechanistic view of the structure of nature.

Iatrochemistry.

Paracelsus (1493-1541) held a completely different view of the goals of alchemy. Under such a name chosen by him (“superior to Celsus”), the Swiss doctor Philipp von Hohenheim went down in history. Paracelsus, like Avicenna, believed that the main task of alchemy was not the search for ways to obtain gold, but the manufacture of medicines. He borrowed from the alchemical tradition the doctrine that there are three main parts of matter - mercury, sulfur, salt, which correspond to the properties of volatility, combustibility and hardness. These three elements form the basis of the macrocosm (Universe) and are associated with the microcosm (man) formed by the spirit, soul and body. Turning to the definition of the causes of diseases, Paracelsus argued that fever and plague come from an excess of sulfur in the body, paralysis occurs with an excess of mercury, and so on. The principle that all iatrochemists adhered to was that medicine is a matter of chemistry, and everything depends on the ability of the doctor to isolate pure principles from impure substances. Under this scheme, all functions of the body were reduced to chemical processes, and the task of the alchemist was to find and prepare chemicals for medical purposes.

The main representatives of the iatrochemical trend were Jan Helmont (1577–1644), a doctor by profession; Francis Silvius (1614-1672), who enjoyed great fame as a physician and eliminated "spiritual" principles from the iatrochemical doctrine; Andreas Libavius (c. 1550–1616), physician from Rothenburg Their research contributed greatly to the formation of chemistry as an independent science.

mechanical philosophy.

With the diminishing influence of iatrochemistry, natural philosophers turned again to the teachings of the ancients about nature. Foreground in the 17th century. atomistic (corpuscular) views came out. One of the most prominent scientists - the authors of the corpuscular theory - was the philosopher and mathematician Rene Descartes. He outlined his views in 1637 in an essay Reasoning about method. Descartes believed that all bodies “consist of numerous small particles of various shapes and sizes, ... which are not so closely adjacent to each other that there are no gaps around them; these gaps are not empty, but filled with ... rarefied matter. Descartes did not consider his “small particles” to be atoms, i.e. indivisible; he stood on the point of view of the infinite divisibility of matter and denied the existence of emptiness. One of Descartes' most prominent opponents was the French physicist and philosopher Pierre Gassendi. Atomism Gassendi was essentially a retelling of the teachings of Epicurus, however, unlike the latter, Gassendi recognized the creation of atoms by God; he believed that God created a certain number of indivisible and impenetrable atoms, of which all bodies are composed; there must be an absolute void between the atoms. In the development of chemistry in the 17th century. a special role belongs to the Irish scientist Robert Boyle. Boyle did not accept the statements of the ancient philosophers, who believed that the elements of the universe can be established speculatively; This is reflected in the title of his book. Skeptic Chemist. Being a supporter of the experimental approach to the definition of chemical elements (which was eventually adopted), he did not know about the existence of real elements, although one of them - phosphorus - almost discovered himself. Boyle is usually credited with introducing the term "analysis" into chemistry. In his experiments on qualitative analysis, he used various indicators, introduced the concept of chemical affinity. Based on the works of Galileo Galilei Evangelista Torricelli, as well as Otto Guericke, who demonstrated the “Magdeburg hemispheres” in 1654, Boyle described the air pump he designed and experiments to determine the elasticity of air using a U-shaped tube. As a result of these experiments, the well-known law on the inverse proportionality of the volume and pressure of air was formulated. In 1668 Boyle became an active member of the newly organized Royal Society of London, and in 1680 he was elected its president.

Technical chemistry.

Scientific advances and discoveries could not but affect technical chemistry, elements of which can be found in the 15th-17th centuries. In the middle of the 15th century blower technology was developed. The needs of the military industry stimulated work to improve the technology of gunpowder production. During the 16th century the production of gold doubled and the production of silver increased ninefold. There are fundamental works on the production of metals and various materials used in construction, in the manufacture of glass, dyeing of fabrics, for the preservation of food products, and leather dressing. With the expansion of the consumption of alcoholic beverages, distillation methods are being improved, new distillation apparatuses are being designed. Numerous production laboratories appear, primarily metallurgical ones. Among the chemical technologists of that time, we can mention Vannoccio Biringuccio (1480–1539), whose classic work O pyrotechnics was printed in Venice in 1540 and contained 10 books dealing with mines, testing of minerals, preparation of metals, distillation, martial arts and fireworks. Another famous treatise About mining and metallurgy, was painted by Georg Agricola (1494–1555). Mention should also be made of Johann Glauber (1604–1670), a Dutch chemist, creator of Glauber's salt.

XVIII CENTURY

Chemistry as a scientific discipline.

From 1670 to 1800 chemistry received official status in curricula leading universities along with natural philosophy and medicine. A textbook by Nicolas Lemery (1645–1715) appeared in 1675. Chemistry course, which gained immense popularity, 13 of its French editions were published, and in addition, it was translated into Latin and many other European languages. In the 18th century scientific chemical societies are being created in Europe and a large number of scientific institutes; their research is closely related to the social and economic needs of society. Practicing chemists appear who are engaged in the manufacture of devices and the preparation of substances for industry.

Phlogiston theory.

In the writings of chemists of the second half of the 17th century. much attention was paid to interpretations of the combustion process. According to the ideas of the ancient Greeks, everything that is capable of burning contains the element of fire, which is released under appropriate conditions. In 1669, the German chemist Johann Joachim Becher tried to rationalize flammability. He suggested that solids consist of three types of "earth", and he took one of the types, which he called "fat earth", for the "principle of combustibility".

A follower of Becher, the German chemist and physician Georg Ernst Stahl transformed the concept of "fat earth" into a generalized doctrine of phlogiston - "the beginning of combustibility". According to Stahl, phlogiston is a certain substance contained in all combustible substances and released during combustion. Stahl argued that the rusting of metals is similar to the burning of wood. Metals contain phlogiston, but rust (dross) no longer contains phlogiston. This gave an acceptable explanation for the process of turning ores into metals: an ore, the content of phlogiston in which is insignificant, is heated on charcoal rich in phlogiston, and the latter turns into ore. Coal turns into ash, and ore into a metal rich in phlogiston. By 1780, the phlogiston theory was almost universally accepted by chemists, although it did not answer a very important question: why does iron become heavier when it rusts, although phlogiston escapes from it? Chemists of the 18th century. this contradiction did not seem so important; the main thing, in their opinion, was to explain the reasons for the change in the appearance of substances.

In the 18th century many chemists worked, whose scientific activity does not fit into the usual schemes for considering the stages and directions of the development of science, and among them a special place belongs to the Russian scientist-encyclopedist, poet, champion of education Mikhail Vasilievich Lomonosov (1711-1765). With his discoveries, Lomonosov enriched almost all areas of knowledge, and many of his ideas were more than a hundred years ahead of the science of that time. In 1756, Lomonosov conducted the famous experiments on firing metals in a closed vessel, which provided indisputable evidence of the conservation of matter in chemical reactions and the role of air in combustion processes: even before Lavoisier, he explained the observed increase in weight during firing of metals by combining them with air. In contrast to the prevailing ideas about caloric, he argued that thermal phenomena are due to the mechanical movement of material particles. He explained the elasticity of gases by the movement of particles. Lomonosov distinguished between the concepts of "corpuscle" (molecule) and "element" (atom), which was generally recognized only in the middle of the 19th century. Lomonosov formulated the principle of the conservation of matter and motion, excluded phlogiston from the number of chemical agents, laid the foundations of physical chemistry, created a chemical laboratory at the St. Petersburg Academy of Sciences in 1748, in which not only scientific work but also practical training for students. He conducted extensive research in areas of knowledge adjacent to chemistry - physics, geology, etc.

Pneumatic chemistry.

The shortcomings of the phlogiston theory were most clearly revealed during the development of the so-called. pneumatic chemistry. The largest representative of this trend was R. Boyle: he not only discovered gas law, now bearing his name, but also designed devices for collecting air. Chemists have received the most important tool for isolating, identifying and studying various "airs". An important step was the invention by the English chemist Stephen Hales (1677–1761) of the "pneumatic bath" in the early 18th century. - a device for trapping gases released when a substance is heated, into a vessel with water, lowered upside down into a bath of water. Later, Hales and Henry Cavendish established the existence of certain gases (“airs”) that differ in their properties from ordinary air. In 1766, Cavendish systematically studied the gas formed during the interaction of acids with certain metals, later called hydrogen. A great contribution to the study of gases was made by the Scottish chemist Joseph Black. He took up the study of gases released during the action of acids on alkalis. Black found that the mineral calcium carbonate, when heated, decomposes with the release of gas and forms lime (calcium oxide). The liberated gas (carbon dioxide - Black called it "bound air") could be recombined with lime to form calcium carbonate. Among other things, this discovery established the inseparability of bonds between solid and gaseous substances.

chemical revolution.

Great success in the evolution of gases and the study of their properties was achieved by Joseph Priestley, a Protestant priest who was passionately engaged in chemistry. Near Leeds (England), where he served, there was a brewery, from where you could get large quantities"bound air" (now we know it was carbon dioxide) for experiments. Priestley discovered that gases could dissolve in water and tried to collect them not over water, but over mercury. So he managed to collect and study nitric oxide, ammonia, hydrogen chloride, sulfur dioxide (of course, these are their modern names). In 1774, Priestley made his most important discovery: he isolated a gas in which substances burned especially brightly. Being a supporter of the theory of phlogiston, he called this gas "dephlogisticated air". The gas discovered by Priestley seemed to be the opposite of "phlogisticated air" (nitrogen) isolated in 1772 by the English chemist Daniel Rutherford (1749–1819). In the "phlogisticated air" the mice died, while in the "dephlogisticated" they were very active. (It should be noted that the properties of the gas isolated by Priestley were described as early as 1771 by the Swedish chemist Carl Wilhelm Scheele, but his message, due to the negligence of the publisher, appeared in print only in 1777.) The great French chemist Antoine Laurent Lavoisier immediately appreciated the significance of Priestley's discovery. In 1775, he prepared an article where he argued that air is not a simple substance, but a mixture of two gases, one of them is Priestley's "dephlogisticated air", which combines with burning or rusting objects, passes from ores to charcoal and is necessary for life. Lavoisier called him oxygen, oxygen, i.e. "producer of acids". The second blow to the theory of elemental elements was dealt after it became clear that water is also not a simple substance, but a product of the combination of two gases: oxygen and hydrogen. All these discoveries and theories, having done away with the mysterious "elements", led to the rationalization of chemistry. Only those substances that can be weighed or whose quantity can be measured in some other way have come to the fore. During the 80s of the 18th century. Lavoisier, in collaboration with other French chemists - Antoine Francois de Fourcroix (1755-1809), Guiton de Morveau (1737-1816) and Claude Louis Berthollet - developed a logical system chemical nomenclature; more than 30 simple substances were described in it, indicating their properties. This labor Method of chemical nomenclature, was published in 1787.

The revolution in the theoretical views of chemists that took place at the end of the 18th century as a result of the rapid accumulation of experimental material under the dominance of the phlogiston theory (albeit independently of it), is usually called the "chemical revolution".

NINETEENTH CENTURY

Composition of substances and their classification.

Lavoisier's advances have shown that the application of quantitative methods can help determine chemical composition substances and elucidation of the laws of their association.

Atomic theory.

The birth of physical chemistry.

By the end of the 19th century the first works appeared in which systematically studied physical properties various substances (boiling and melting points, solubility, molecular weight). Such studies were initiated by Gay-Lussac and van't Hoff, who showed that the solubility of salts depends on temperature and pressure. In 1867, the Norwegian chemists Peter Waage (1833–1900) and Kato Maximilian Guldberg (1836–1902) formulated the law of mass action, according to which the reaction rate depends on the concentrations of the reactants. The mathematical apparatus they used made it possible to find a very important quantity that characterizes any chemical reaction - the rate constant.

Chemical thermodynamics.

Meanwhile, chemists turned to the central question of physical chemistry, the effect of heat on chemical reactions. By the middle of the 19th century. physicists William Thomson (Lord Kelvin), Ludwig Boltzmann and James Maxwell developed new views on the nature of heat. Rejecting Lavoisier's caloric theory, they presented heat as the result of motion. Their ideas were developed by Rudolf Clausius. He developed the kinetic theory, according to which such quantities as volume, pressure, temperature, viscosity and reaction rate can be considered based on the idea of continuous movement of molecules and their collisions. Simultaneously with Thomson (1850), Clasius gave the first formulation of the second law of thermodynamics, introduced the concepts of entropy (1865), an ideal gas, and the free path of molecules.

The thermodynamic approach to chemical reactions was applied in his works by August Friedrich Gorstmann (1842–1929), who, based on the ideas of Clausius, tried to explain the dissociation of salts in solution. In 1874–1878 the American chemist Josiah Willard Gibbs undertook a systematic study of the thermodynamics of chemical reactions. He introduced the concept of free energy and chemical potential, explained the essence of the law of mass action, applied thermodynamic principles in studying the equilibrium between different phases at different temperatures, pressures and concentrations (the phase rule). Gibbs' work laid the foundation for modern chemical thermodynamics. The Swedish chemist Svante August Arrhenius created the theory of ionic dissociation, which explains many electrochemical phenomena, and introduced the concept of activation energy. He also developed electrochemical method measurements of the molecular weight of dissolved substances.

A major scientist, thanks to whom physical chemistry was recognized as an independent field of knowledge, was the German chemist Wilhelm Ostwald, who applied Gibbs' concepts in the study of catalysis. In 1886 he wrote the first textbook on physical chemistry, and in 1887 he founded (together with van't Hoff) the journal Physical Chemistry (Zeitschrift für physikalische Chemie).

THE TWENTIETH CENTURY

New structural theory.

With development physical theories about the structure of atoms and molecules, such old concepts as chemical affinity and transmutation were rethought. New ideas about the structure of matter arose.

Model of the atom.

In 1896, Antoine Henri Becquerel (1852–1908) discovered the phenomenon of radioactivity, discovering the spontaneous emission of subatomic particles by uranium salts, and two years later, the spouses Pierre Curie and Marie Skłodowska-Curie isolated two radioactive elements: polonium and radium. In subsequent years, it was found that radioactive substances emit three types of radiation: a-particles, b-particles and g-rays. Together with the discovery of Frederick Soddy, which showed that during radioactive decay, some substances are transformed into others, all this gave a new meaning to what the ancients called transmutation.

In 1897, Joseph John Thomson discovered the electron, the charge of which was measured with high accuracy in 1909 by Robert Milliken. In 1911, Ernst Rutherford, based on Thomson's electronic concept, proposed a model of the atom: a positively charged nucleus is located in the center of the atom, and negatively charged electrons revolve around it. In 1913 Niels Bohr, using the principles quantum mechanics, showed that electrons can be located not in any, but in strictly defined orbits. The Rutherford-Bohr planetary quantum model of the atom forced scientists to take a new approach to explaining the structure and properties of chemical compounds. The German physicist Walter Kossel (1888-1956) suggested that the chemical properties of an atom are determined by the number of electrons in its outer shell, and the formation of chemical bonds is determined mainly by the forces of electrostatic interaction. American scientists Gilbert Newton Lewis and Irving Langmuir formulated electronic theory chemical bond. In accordance with these ideas, the molecules of inorganic salts are stabilized by electrostatic interactions between their constituent ions, which are formed during the transition of electrons from one element to another (ionic bond), and the molecules organic compounds– due to the socialization of electrons ( covalent bond). These ideas underlie modern ideas about the chemical bond.

New research methods.

All new ideas about the structure of matter could be formed only as a result of the development in the 20th century. experimental technique and the emergence of new research methods. The discovery in 1895 by Wilhelm Konrad Roentgen of X-rays served as the basis for the subsequent creation of the method of X-ray crystallography, which makes it possible to determine the structure of molecules from the diffraction pattern. x-rays on crystals. Using this method, the structure of complex organic compounds was deciphered - insulin, deoxyribonucleic acid (DNA), hemoglobin, etc. With the creation of the atomic theory, new powerful spectroscopic methods appeared that provide information about the structure of atoms and molecules. Various biological processes, as well as the mechanism of chemical reactions, are studied using radioisotope labels; Radiation methods are also widely used in medicine.

Biochemistry.

This scientific discipline, which deals with the study of the chemical properties of biological substances, was at first one of the branches of organic chemistry. It emerged as an independent region in the last decade of the 19th century. as a result of research on the chemical properties of substances of plant and animal origin. One of the first biochemists was the German scientist Emil Fischer. He synthesized substances such as caffeine, phenobarbital, glucose, many hydrocarbons, made a great contribution to the science of enzymes - protein catalysts, first isolated in 1878. The formation of biochemistry as a science was facilitated by the creation of new analytical methods. In 1923, the Swedish chemist Theodor Svedberg designed an ultracentrifuge and developed a sedimentation method for determining the molecular weight of macromolecules, mainly proteins. Svedberg's assistant Arne Tiselius (1902-1971) in the same year created the method of electrophoresis, a more advanced method for separating giant molecules, based on the difference in the speed of migration of charged molecules in an electric field. At the beginning of the 20th century Russian chemist Mikhail Semenovich Tsvet (1872–1919) described a method for separating plant pigments by passing their mixture through a tube filled with an adsorbent. The method was called chromatography. In 1944, British chemists Archer Martin and Richard Synge proposed new version method: they replaced the adsorbent tube with filter paper. This is how paper chromatography appeared - one of the most common analytical methods in chemistry, biology and medicine, with the help of which, in the late 1940s and early 1950s, it was possible to analyze mixtures of amino acids resulting from the breakdown of various proteins and determine the composition of proteins. As a result of painstaking research, the order of amino acids in the insulin molecule was established (Frederick Sanger), and by 1964 this protein was synthesized. Now many hormones, medicines, vitamins are obtained by biochemical synthesis methods.

Industrial chemistry.

Probably the most important stage in the development of modern chemistry was the creation in the 19th century of various research centers engaged, in addition to fundamental, also applied research. At the beginning of the 20th century a number of industrial corporations created the first industrial research laboratories. In the USA, the chemical laboratory DuPont was founded in 1903, and in 1925 the laboratory of the Bell firm. After the discovery and synthesis of penicillin in the 1940s, and then other antibiotics, large pharmaceutical companies appeared, employing professional chemists. Works in the field of chemistry were of great practical importance. macromolecular compounds. One of its founders was the German chemist Hermann Staudinger (1881–1965), who developed the theory of the structure of polymers. An intensive search for ways to obtain linear polymers led in 1953 to the synthesis of polyethylene (Karl Ziegler,), and then other polymers with desired properties. Today, the production of polymers is the largest branch of the chemical industry.

Not all advances in chemistry have been good for man. In the 19th century in the production of paints, soaps, textiles used hydrochloric acid and sulfur, which posed a great danger to environment. In the 20th century the production of many organic and inorganic materials has increased due to the recycling of used substances, as well as through the processing of chemical waste that poses a risk to human health and the environment.

Literature:

Figurovsky N.A. Outline of the general history of chemistry. M., 1969
Juah M. History of chemistry. M., 1975
Azimov A. Short story chemistry. M., 1983

He laid the foundations of quantum theory. Clemens Winkler and R. Knitch developed the basis for the industrial synthesis of sulfuric acid by the contact method.

1901 - Eugene Demarce discovered the rare earth element europium.

1903 - Mikhail Stepanovich Tsvet laid the foundations for the method of adsorption chromatography. Emil Fischer established that proteins are built from alpha-amino acids; carried out the first syntheses of peptides.

1905 - Alfred Werner proposed a modern version (long-period) of the Periodic Table of the Elements.

1907 - Georges Urbain discovered the rare earth element lutetium, the last of the stable rare earth elements.

1908 - Wilhelm Ostwald (Nobel Prize winner in 1909) developed the fundamentals of the technology for the production of nitric acid by the catalytic oxidation of ammonia.

1909 - Søren Sørensen introduced the pH indicator of the acidity of the medium - pH.
Irving Langmuir (Nobel Prize winner 1932) developed the foundations of the modern theory of adsorption.

1910 - Sergei Vasilyevich Lebedev received the first sample of synthetic butadiene rubber.

1911 - Ernest Rutherford (Nobel Prize winner in 1908) proposed a nuclear (planetary) model of the atom.

1913 - Niels Bohr (Nobel Prize winner in 1922) formulated the basic postulates of the quantum theory of the atom, according to which electrons in an atom have a certain energy and, as a result, can rotate in the electron shell only at certain energy levels.
Casimir Fajans and Frederick Soddy (Nobel Prize winner in 1921) formulated the law of radioactive shifts (thereby the structure of radioactive families was linked to the structure of the Periodic Table of Elements).
A. Van den Broek suggested that the number of an element in the Periodic system is numerically equal to the charge of its atom.

1914 - R. Meyer proposed to place all rare earth elements in a secondary subgroup of group III of the Periodic system.

1915 - I. Stark introduced the concept of "valence electrons"

1916 - Walter Kossel and Gilbert Lewis developed the theory of atomic bonding and ionic bonding.
Nikolai Dmitrievich Zelinsky designed a gas mask.

1919 - Ernest Rutherford (Nobel laureate 1908) carried out the first nuclear reaction artificial transformation of elements.

1920 - The most important studies of the structure of the atom, which led to modern ideas about the model of the atom. These studies involved Louis De Broglie (1929 Nobel Prize winner) (wave nature of the electron), Erwin Schrödinger (1933 Nobel Prize winner) (introduced the fundamental equation of quantum mechanics), Werner Heisenberg (1932 Nobel Prize winner), Paul Dirac (Nobel Prize winner 1933).

1923 - György Hevesy and D. Koster discovered hafnium.
Johannes Brønsted proposed to consider substances that donate protons as acids, and substances that accept protons as bases.

1925 - Wolfgang Pauli formulated the principle of prohibition.
G. Uhlenbeck and S. Goudsmit introduced the concept of the electron spin.

1931 - Erich Hückel laid the foundations of the quantum chemistry of organic compounds. Formulated (4 n+ 2) - the rule of aromatic stability, which establishes whether a substance belongs to the aromatic series. Sergei Vasilyevich Lebedev solved the problems of industrial production of synthetic rubber.

1932 - J. Chadwick (1935 Nobel Prize winner) discovered the neutron.
D. D. Ivanenko proposed a proton-neutron model of the atomic nucleus.
Linus Pauling (1954 Nobel Prize winner) quantified the concept of electronegativity, proposed a scale for electronegativity, and expressed the relationship between electronegativity and chemical bond energy.

1933 - P. Blackett and G. Occhialini discovered the positron.

1934 - Irene and Joliot Curie (Nobel Prize winners in 1935) discovered the phenomenon of artificial radioactivity.

1937 - Carlo Perrier and Emilio Segre discovered a new element - the first artificially synthesized element technetium with Z = 43.

1939 - Margaret Perey discovered francium - an element with Z = 87. Technologies for the industrial production of artificial fibers (nylon, perlon) were developed

1940 - D. Corson, C. Mackenzie, E. Segre synthesized astatine (Z = 85). E. Macmillan (Nobel Prize winner in 1951), F. Ableson synthesized the first transuranium element neptunium with Z = 93.
Glenn Seaborg, E. Macmillan (1951 Nobel laureates), J. Kennedy, A. Wahl synthesized plutonium with Z = 94 .

1944 - Glenn Seaborg (1951 Nobel Prize winner), R. James, Albert Ghiorso synthesized curium with Z = 96.
Glenn Seaborg put forward the actinoid concept of the placement of transuranium elements in the Periodic Table.

1945 - Glenn Seaborg (Nobel Prize winner in 1951), R. James, P. Morgan, A. Ghiorso synthesized americium with Z = 95.

1947 - E. Chargaff was the first to obtain pure DNA preparations.

1949 - Glenn Seaborg (Nobel Prize winner in 1951), S. Thompson, Albert Ghiorso synthesized berkelium (Z = 97) and californium (Z = 98).

1951 - Linus Pauling (Nobel Prize winner 1954) developed the polypeptide helix model.
V.M. Klechkovsky formulated the rule ( n+ l) - fillings of electron shells and subshells of atoms as Z increases.
T. Keely, P. Poson synthesized a non-benzenoid aromatic compound of a "sandwich" structure - ferrocene (C 5 H 5) 2 Fe.

1952 - Glenn Seaborg (Nobel Prize winner 1951), Albert Ghiorso and others discovered einsteinium (Z = 99) and fermium (Z = 100).

1953 - J. Watson and F. Crick (1962 Nobel Prize winners) proposed a DNA model - a double helix of polynucleotide strands connected by hydrogen "bridges".
A. Todd and D. Brown developed a scheme for the structure of RNA.

1954 - K. Ziegler, J. Nutt (Nobel Prize winners in 1963) discovered mixed organometallic catalysts for the industrial synthesis of polymers.

1955 - Glenn Seaborg (Nobel Prize winner 1951) and others synthesized mendelevium (Z = 101)
N. N. Semenov and S. Hinshelvud (Nobel Prize winners in 1962) conducted fundamental studies of the mechanism of radical chemical reactions.

1958 - A. Kornberg and S. Ochoa discovered the mechanism of RNA and DNA biosynthesis (Nobel Prize winners in 1959).

1961 - A new International scale of atomic masses was established - 1/12 of the mass of the 12 C isotope was taken as a unit. Albert Ghiorso, T. Sikkeland, A. Laroche, R. Latimer synthesized lawrencium (Z = 103).

1962 - The first compounds of noble gases were obtained.

1963 - R. Merrifield developed a solid-phase method for peptide synthesis; complete synthesis of insulin was carried out - the first chemical protein synthesis.

1964 - 1984 - Georgy Nikolaevich Flerov and his colleagues synthesized new elements - kurchatovium (Z = 104) (1964) and nilsborium (Z = 105) (1970). Yuri Tsolakovich Oganesyan and coworkers obtained elements with Z = 106 (1974), Z = 107 (1976), Z = 108 (1982), Z = 110 (1986). Peter Armbruster and collaborators synthesized the element with Z = 109 (1984).

1974 - A.S. Khokhlov established the sequence of amino acids in the antibiotic actinoxanthin.

1975 - I.V. Berezin discovered the phenomenon of bioelectrocatalysis. D. Demarto received a compound with a xenon - nitrogen bond: FeXeN (SO 2 F) 2.

1975-1980 - R.Z. Sagdeev and his collaborators established the influence of magnetic fields on chemical processes.

1976 - J. Wayne discovered a new prostaglandin - prostacyclin and established its chemical structure.

1977-1980 - W. Gilbert proposed a method for deciphering the primary structure of DNA, based on the principle of localization of bases according to the size of DNA fragments. E.A. Shilov carried out research on the photocatalytic production of hydrogen and oxygen from water. The first "organic metals" were obtained - polyacetylene (H. Shirakawa), polypyrrole (A. Diaz).

1978-1980 - M. V. Alfimov created theoretical basis silverless photographic processes.

1980-1990 - the beginning of the application of methods of supramolecular chemistry - the synthesis of various products using macrocyclic compounds such as crown ethers and cryptands. Development of methods for obtaining "organic metals" - derivatives of tetrathiofulvalene, metal phthalocyanines, etc.

1984 - S. Hannessian synthesized a new effective antibiotic quantamycin. Simultaneously and independently, German (Darmstadt, G. Münzenberg et al.) and Russian scientists (Dubna, Yu.Ts. Oganesyan et al.) obtained the 108th element.

1985 - H. Kroto, R. Smalley discovered fullerene C 60 - a new modification of carbon. 1986 - K. Bednorz and A. Müller obtained samples of superconducting (at 90 K) ceramics based on oxides of barium, copper and yttrium. S. Satpazi and R. Disch proved the stability of fullerene C 60 .

1987 - For the first time, iron(VIII) oxide was obtained by anodic dissolution of iron (V. I. Spitsyn and co-workers). K. Gu and co-workers obtained modified lanthanum cuprite LaCu 2 O 4 superconducting at 93 K. German scientists (Darmstadt, G. Münzenberg et al.) obtained the 109th element.

1991 - Synthesis of compounds related to fullerene - carbon nanotubes.

1996 - 1997 - Development of a molecular layering method for precision synthesis of regular solids. Obtaining lyotropic and thermotropic liquid crystal polymers.

1999 - The first organic laser based on tetracene derivatives. Synthesis and the beginning of the study of protonium (an atom consisting of a proton and an antiproton).

1990-2000 - Production by nuclear fusion of chemical elements with numbers 110, 111, 112, 114 and 116. Chemical synthesis of proteins and nucleotides by genetic engineering.

Almost everyone who is interested in the history of the development of science, engineering and technology has at least once in his life thought about which way the development of mankind could go without knowledge of mathematics or, for example, if we didn’t have such a necessary subject as a wheel, which became almost basis for human development. However, only key discoveries are often considered and paid attention to, while less known and widespread discoveries are sometimes simply not mentioned, which, however, does not make them insignificant, because each new knowledge gives humanity the opportunity to climb a step higher in its development.

The 20th century and its scientific discoveries have turned into a real Rubicon, crossing which progress has accelerated its pace several times, identifying itself with a sports car that is impossible to keep up with. In order to stay on the crest of the scientific and technological wave now, not hefty skills are needed. Of course you can read scientific journals, various articles and works of scientists who are struggling to solve a particular problem, but even in this case it will not be possible to keep up with progress, and therefore it remains to catch up and observe.

As you know, in order to look into the future, you need to know the past. Therefore, today we will talk about the 20th century, the century of discoveries, which changed the way of life and the world around us. It should be noted right away that this will not be a list of the best discoveries of the century or any other top, it will be a brief overview of some of those discoveries that have changed, and possibly are changing the world.

In order to talk about discoveries, it is necessary to characterize the concept itself. We take the following definition as a basis:

Discovery is a new achievement made in the process scientific knowledge nature and society; the establishment of previously unknown, objectively existing patterns, properties and phenomena of the material world.

Top 25 Great Scientific Discoveries of the 20th Century

There is no doubt that all these discoveries are only a small part of what the 20th century showed to society, and it cannot be said that only these discoveries were significant, and all the rest became just a background, this is not at all the case.

It was the last century that showed us the new boundaries of the Universe, saw the light, quasars were discovered (super-powerful sources of radiation in our Galaxy), the first carbon nanotubes with unique superconductivity and strength.

All these discoveries, one way or another, are just the tip of the iceberg, which includes more than a hundred significant discoveries over the past century. Naturally, all of them have become a catalyst for changes in the world in which we now live, and the fact remains undeniable that the changes do not end there.

The 20th century can be safely called, if not the “golden”, then certainly the “silver” age of discoveries, but looking back and comparing new achievements with the past, it seems that in the future we will have quite a few interesting great discoveries, in fact, the successor of the last century, the current XXI only confirms these views.

Chemistry is a science closely related to physics. It considers mainly the transformations of substances, studies elements (the simplest substances formed by identical atoms) and complex substances consisting of molecules (combinations of different atoms).

In the second half of the XVIII and early XIX century in the works of scientists was dominated by the study and description of the properties of chemical elements and their compounds. The oxygen theory of Lavoisier (1743-1794) and the atomic theory of Dalton (1766-1844) laid the foundations of theoretical chemistry. The discoveries caused by the atomic and molecular theory began to play a significant role in industrial practice.

Atomistic ideas about the structure of matter have given rise to many theoretical problems. It was necessary to find out what happens to the atoms that form molecular structures? Do atoms retain their properties as part of molecules, and how do they interact with each other? Is the atom really simple and indivisible? These and other questions needed to be addressed.

Without atomic theory, it was impossible to create a theory of ions, and without understanding the ionic state of matter, it was impossible to develop a theory of electrolytic dissociation, and without it, to understand the true meaning of analytical reactions, and then to understand the role of an ion as a complexing agent, etc.

The development of the problems of organic chemistry led to the creation of the doctrine of substitution, the theory of types, the doctrine of homology and valency. The discovery of isomerism put forward the most important task - to study the dependence of the physicochemical properties of compounds on their composition and structure. Studies of isomers have clearly shown that the physical and chemical properties of substances depend not only on the arrangement of atoms in molecules.

By the middle of the 19th century, on the basis of the doctrine of chemical compounds and chemical elements, on the basis of atomic and molecular theory, it became possible to create a theory of chemical structure and discover the periodic law of chemical elements. In the second half of the 19th century, there was a gradual transformation of chemistry from a descriptive science that studies chemical elements, the composition and properties of their compounds, into a theoretical science that studies the causes and mechanism of the transformation of substances. It became possible to manage chemical process by converting substances, natural and synthetic, into useful products. By the end of the 19th century, tens of thousands of new organic and not organic matter. Fundamental laws have been discovered and generalizing theories have been created. Achievements chemical science introduced into industry. Chemical laboratories and physico-chemical institutes were built and well equipped.

Chemistry belongs to the category of sciences that, through their practical successes, have contributed to the improvement of the well-being of mankind. At present, the development of chemistry has a number characteristic features. Firstly, this is the blurring of the boundaries between the main sections of chemistry. For example, thousands of compounds can now be named that cannot be unambiguously classified as organic or inorganic. Secondly, the development of research at the intersection of physics and chemistry has given rise to big number specific works, which eventually formed into independent scientific disciplines. It suffices to name, for example, thermochemistry, electrochemistry, radiochemistry, etc. At the same time, the “splitting >> of chemistry proceeded according to the objects of study. In this direction, disciplines have arisen that study:

1) individual sets of chemical elements (chemistry of light elements, rare earth elements).

2) individual elements (for example, the chemistry of fluorine, phosphorus and silicon).

3) separate classes of compounds (chemistry of hydrides, semiconductors).

4) chemistry of special groups of compounds, which includes elementary and coordination chemistry.

Thirdly, for chemistry, biology, geology, cosmology were partners for integration, which led to the birth of biochemistry, geochemistry, etc. A process of “hybridization” took place.

One of the important tasks of modern chemistry is the prediction of the conditions for the synthesis of substances with predetermined properties and the determination of their physical and chemical parameters.

Let us characterize the main directions of modern chemistry. Chemistry is usually divided into five sections: inorganic, organic, physical, analytical and macromolecular chemistry.

Main tasks inorganic chemistry are: the study of the structure of compounds, the establishment of a connection between the structure and properties and reactivity. Methods for the synthesis and deep purification of substances are also being developed. Much attention is paid to the kinetics and mechanism of inorganic reactions, their catalytic acceleration and deceleration. For syntheses, methods of physical influence are increasingly used: ultra-high temperatures and pressures, ionizing radiation, ultrasound, magnetic fields. Many processes take place under conditions of combustion or low-temperature plasma. chemical reactions often combined with the production of fibrous, layered and single-crystal materials, with the manufacture of electronic circuits.

Inorganic compounds are used as structural materials for all industries, including space technology, as fertilizer and feed additives, nuclear and rocket fuel, pharmaceutical materials.

Organic chemistry is the largest branch of chemical science. If the number of known inorganic substances is about 5 thousand, then in the early 80s more than 4 million organic substances were known. The great importance of polymer chemistry is generally recognized. So, back in 1910, SV. Lebedev developed an industrial method for producing butadiene, and rubber from it.

In 1936, W. Carothers synthesized "nylon", having discovered a new type of synthetic polymers - polyamides. In 1938, R. Plunket accidentally discovers Teflon, which created an era for the synthesis of fluoropolymers with unique thermal stability, "eternal" lubricating oils (plastics and elastomers) are created, which are widely used by space and jet technology, chemical and electrical industries. Thanks to these and many other discoveries, the chemistry of macromolecular compounds (or polymers) grew out of organic chemistry.

Extensive studies of organophosphorus compounds (A.E. Arbuzov), which began in the 1930s and 1940s, led to the discovery of new types of physiologically active compounds - medicines, toxic substances, plant protection products, etc.

The chemistry of dyes practically gave rise to the chemical industry. For example, the chemistry of aromatic and heterocyclic compounds created the first branch of the chemical industry, the production of which now exceeds 1 billion tons, and gave rise to new industries - the production of fragrant and medicinal substances.

Penetration of organic chemistry into related fields - biochemistry, biology, medicine, Agriculture- led to the study of the properties, the establishment of the structure and the synthesis of vitamins, proteins, nucleic acids, antibiotics, new growth agents and pest control agents.

Tangible results are obtained by the use of mathematical modeling. If the discovery of any pharmaceutical drug or insecticide required the synthesis of 10-20 thousand substances, then with the help of mathematical modeling, the choice is made only as a result of the synthesis of several dozen compounds.

The role of organic chemistry in biochemistry cannot be overestimated. So, in 1963, V. Vigno synthesized insulin, oxytocin (a peptide hormone), vasopressin (a hormone has an antidiuretic effect), and bradykikin (it has a vasodilating effect) were also synthesized. Semi-automatic methods for the synthesis of polypeptides have been developed (R. Merifield, 1962).

The pinnacle of the achievements of organic chemistry in genetic engineering was the first synthesis of an active gene (X. Korana, 1976). In 1977, a gene encoding the synthesis of human insulin was synthesized, and in 1978, a somato-statin gene (capable of inhibiting insulin secretion, a peptide hormone) was synthesized.

Physical chemistry explains chemical phenomena and establishes their general patterns. The physical chemistry of the last decades is characterized by the following features. As a result of the development of quantum chemistry (uses the ideas and methods quantum physics to explain chemical phenomena) many problems of the chemical structure of substances and the mechanism of reactions are solved on the basis of theoretical calculations. Along with this, physical research methods are widely used - X-ray structural analysis, electron diffraction, spectroscopy, methods based on the use of isotopes, etc.

Analytical chemistry considers the principles and methods of studying the chemical composition of a substance. Includes quantitative and qualitative analysis. Modern methods analytical chemistry associated with the need to obtain semiconductor and other materials of high frequency. To solve these problems, sensitive methods have been developed: activation analysis, chemical-spectral analysis, etc.

Activation analysis is based on the measurement of radiation energy and half-lives radioactive isotopes formed in the test substance when it is irradiated with nuclear particles.

Chemical-spectral analysis consists in the preliminary isolation of the elements to be determined from the sample and in the preparation of their concentrate, which is analyzed by emission methods. spectral analysis(method of elemental analysis by atomic emission spectra). These methods make it possible to determine 10~7-10~8% of impurities.