Element 115 of the periodic table - moscovium - is a superheavy synthetic element with the symbol Mc and atomic number 115. It was first obtained in 2003 by a joint team of Russian and American scientists at the Joint Institute nuclear research(JINR) in Dubna, Russia. In December 2015, it was recognized as one of the four new elements by the Joint Working Group of International Scientific Organizations IUPAC/IUPAP. On November 28, 2016, it was officially named in honor of the Moscow region, where JINR is located.
Characteristic
Element 115 of the periodic table is an extremely radioactive substance: its most stable known isotope, moscovium-290, has a half-life of just 0.8 seconds. Scientists classify moscovium as a non-transition metal, with a number of characteristics similar to bismuth. In the periodic table, it belongs to the transactinide elements of the p-block of the 7th period and is placed in group 15 as the heaviest pnictogen (nitrogen subgroup element), although it has not been confirmed to behave like a heavier homologue of bismuth.
According to calculations, the element has some properties similar to lighter homologues: nitrogen, phosphorus, arsenic, antimony and bismuth. At the same time, it demonstrates several significant differences from them. To date, about 100 moscovium atoms have been synthesized, which have mass numbers from 287 to 290.
Physical properties
The valence electrons of element 115 of the periodic table, moscovium, are divided into three subshells: 7s (two electrons), 7p 1/2 (two electrons), and 7p 3/2 (one electron). The first two of them are relativistically stabilized and, therefore, behave like noble gases, while the latter are relativistically destabilized and can easily participate in chemical interactions. Thus, the primary ionization potential of moscovium should be about 5.58 eV. According to calculations, moscovium should be a dense metal due to its high atomic weight with a density of about 13.5 g/cm 3 .
Estimated design characteristics:
- Phase: solid.
- Melting point: 400°C (670°K, 750°F).
- Boiling point: 1100°C (1400°K, 2000°F).
- Specific heat of fusion: 5.90-5.98 kJ/mol.
- Specific heat of vaporization and condensation: 138 kJ/mol.
Chemical properties
The 115th element of the periodic table is third in the row chemical elements 7p and is the heaviest member of group 15 on the periodic table, ranking below bismuth. Chemical interaction of moscovium in aqueous solution due to the characteristics of Mc + and Mc 3+ ions. The former are presumably easily hydrolyzed and form ionic bonds with halogens, cyanides and ammonia. Muscovy(I) hydroxide (McOH), carbonate (Mc 2 CO 3), oxalate (Mc 2 C 2 O 4) and fluoride (McF) must be dissolved in water. The sulfide (Mc 2 S) must be insoluble. Chloride (McCl), bromide (McBr), iodide (McI) and thiocyanate (McSCN) are slightly soluble compounds.
Moscovium(III) fluoride (McF 3) and thiosonide (McS 3) are presumably insoluble in water (similar to the corresponding bismuth compounds). While chloride (III) (McCl 3), bromide (McBr 3) and iodide (McI 3) should be readily soluble and easily hydrolyzed to form oxohalides such as McOCl and McOBr (also similar to bismuth). Moscovium(I) and (III) oxides have similar oxidation states, and their relative stability depends largely on which elements they react with.
Uncertainty
Due to the fact that element 115 of the periodic table is synthesized experimentally only once, its exact characteristics are problematic. Scientists have to rely on theoretical calculations and compare them with more stable elements with similar properties.
In 2011, experiments were carried out to create isotopes of nihonium, flerovium and moscovium in reactions between “accelerators” (calcium-48) and “targets” (american-243 and plutonium-244) to study their properties. However, the “targets” included impurities of lead and bismuth and, therefore, some isotopes of bismuth and polonium were obtained in nucleon transfer reactions, which complicated the experiment. Meanwhile, the data obtained will help scientists in the future study in more detail heavy homologues of bismuth and polonium, such as moscovium and livermorium.
Opening
The first successful synthesis of element 115 of the periodic table was a joint work of Russian and American scientists in August 2003 at JINR in Dubna. The team led by nuclear physicist Yuri Oganesyan, in addition to domestic specialists, included colleagues from Lawrence Livermore National Laboratory. Researchers published information in the Physical Review on February 2, 2004 that they bombarded americium-243 with calcium-48 ions at the U-400 cyclotron and obtained four atoms of the new substance (one 287 Mc nucleus and three 288 Mc nuclei). These atoms decay (decay) by emitting alpha particles to the element nihonium in about 100 milliseconds. Two heavier isotopes of moscovium, 289 Mc and 290 Mc, were discovered in 2009–2010.
Initially, IUPAC could not approve the discovery of the new element. Confirmation from other sources was required. Over the next few years, the later experiments were further evaluated, and the Dubna team's claim to have discovered element 115 was once again put forward.
In August 2013, a team of researchers from Lund University and the Heavy Ion Institute in Darmstadt (Germany) announced that they had repeated the 2004 experiment, confirming the results obtained in Dubna. Further confirmation was published by a team of scientists working at Berkeley in 2015. In December 2015, a joint working group IUPAC/IUPAP recognized the discovery of this element and gave priority to the discovery to the Russian-American team of researchers.
Name
In 1979, according to the IUPAC recommendation, it was decided to name element 115 of the periodic table “ununpentium” and denote it with the corresponding symbol UUP. Although the name has since been widely used to refer to the undiscovered (but theoretically predicted) element, it has not caught on within the physics community. Most often, the substance was called that way - element No. 115 or E115.
On December 30, 2015, the discovery of a new element was recognized by the International Union of Pure and Applied Chemistry. According to the new rules, discoverers have the right to propose their own name for a new substance. At first it was planned to name element 115 of the periodic table “langevinium” in honor of the physicist Paul Langevin. Later, a team of scientists from Dubna, as an option, proposed the name “Moscow” in honor of the Moscow region, where the discovery was made. In June 2016, IUPAC approved the initiative and officially approved the name "moscovium" on November 28, 2016.
A lot of different things and objects, living and inanimate bodies of nature surround us. And they all have their own composition, structure, properties. In living beings, complex biochemical reactions occur that accompany vital processes. Nonliving bodies perform various functions in nature and life biomass and have a complex molecular and atomic composition.
But all together the objects of the planet have common feature: They are made up of many tiny structural particles called atoms of chemical elements. So small that they cannot be seen with the naked eye. What are chemical elements? What characteristics do they have and how did you know about their existence? Let's try to figure it out.
Concept of chemical elements
In the generally accepted understanding, chemical elements are just a graphical representation of atoms. The particles that make up everything that exists in the Universe. That is, the following answer can be given to the question “what are chemical elements”. These are complex small structures, collections of all isotopes of atoms, combined common name, having their own graphic designation (symbol).
To date, 118 elements are known to be discovered both naturally and synthetically, through nuclear reactions and the nuclei of other atoms. Each of them has a set of characteristics, its own location in common system, history of discovery and name, and also plays a certain role in nature and the life of living beings. The science of chemistry studies these features. Chemical elements are the basis for building molecules, simple and complex compounds, and therefore chemical interactions.
History of discovery
The very understanding of what chemical elements are came only in the 17th century thanks to the work of Boyle. It was he who first spoke about this concept and gave it the following definition. These are indivisible small simple substances from which everything around is composed, including all complex ones.
Before this work, the dominant views of alchemists were those who recognized the theory of the four elements - Empidocles and Aristotle, as well as those who discovered “combustible principles” (sulfur) and “metallic principles” (mercury).
Almost the entire 18th century, the completely erroneous theory of phlogiston was widespread. However, already at the end of this period, Antoine Laurent Lavoisier proves that it is untenable. He repeats Boyle's formulation, but at the same time supplements it with the first attempt to systematize all elements known at that time, dividing them into four groups: metals, radicals, earths, non-metals.
The next big step in understanding what chemical elements are comes from Dalton. He is credited with the discovery of atomic mass. Based on this, he distributes some of the known chemical elements in order of increasing atomic mass.
The steadily intensive development of science and technology allows us to make a number of discoveries of new elements in the composition of natural bodies. Therefore, by 1869 - the time of the great creation of D.I. Mendeleev - science became aware of the existence of 63 elements. The work of the Russian scientist became the first complete and forever established classification of these particles.
The structure of the chemical elements was not established at that time. It was believed that the atom was indivisible, that it was the smallest unit. With the discovery of the phenomenon of radioactivity, it was proven that it is divided into structural parts. Almost everyone exists in the form of several natural isotopes (similar particles, but with a different number of neutron structures, which changes the atomic mass). Thus, by the middle of the last century, it was possible to achieve order in the definition of the concept of a chemical element.
Mendeleev's system of chemical elements
The scientist based it on the difference in atomic mass and managed to ingeniously arrange all the known chemical elements in increasing order. However, all the depth and genius of it scientific thinking and the foresight was that Mendeleev left empty seats in his system, open cells for still unknown elements, which, according to the scientist, will be discovered in the future.
And everything turned out exactly as he said. Mendeleev's chemical elements filled all the empty cells over time. Every structure predicted by the scientist was discovered. And now we can safely say that the system of chemical elements is represented by 118 units. True, the last three discoveries have not yet been officially confirmed.
The system of chemical elements itself is displayed graphically in a table in which the elements are arranged according to the hierarchy of their properties, nuclear charges and structural features electron shells their atoms. So, there are periods (7 pieces) - horizontal rows, groups (8 pieces) - vertical, subgroups (main and secondary within each group). Most often, two rows of families are placed separately in the lower layers of the table - lanthanides and actinides.
The atomic mass of an element is made up of protons and neutrons, the combination of which is called the “mass number”. The number of protons is determined very simply - it is equal to the atomic number of the element in the system. And since the atom as a whole is an electrically neutral system, that is, having no charge at all, the number of negative electrons is always equal to the number of positive proton particles.
Thus, the characteristics of a chemical element can be given by its position in the periodic table. After all, almost everything is described in the cell: serial number, which means electrons and protons, atomic mass (the average value of all existing isotopes of a given element). You can see in which period the structure is located (this means that electrons will be located on so many layers). It is also possible to predict the number of negative particles at the last energy level for elements of the main subgroups - it is equal to the number of the group in which the element is located.
The number of neutrons can be calculated by subtracting from mass number protons, that is, the atomic number. Thus, it is possible to obtain and compile an entire electron-graphic formula for each chemical element, which will accurately reflect its structure and show the possible and manifested properties.
Distribution of elements in nature
An entire science is studying this issue - cosmochemistry. The data shows that the distribution of elements across our planet follows the same patterns in the Universe. The main source of nuclei of light, heavy and medium atoms are nuclear reactions occurring in the interior of stars - nucleosynthesis. Thanks to these processes, the Universe and outer space supplied our planet with all available chemical elements.
In total, of the known 118 representatives in natural sources, 89 have been discovered by people. These are the fundamental, most common atoms. Chemical elements were also synthesized artificially by bombarding nuclei with neutrons (laboratory nucleosynthesis).
The most numerous are the simple substances of elements such as nitrogen, oxygen, and hydrogen. Carbon is included in all organic matter, which means it also occupies a leading position.
Classification according to the electronic structure of atoms
One of the most common classifications of all chemical elements of a system is their distribution based on their electronic structure. According to how much energy levels is part of the shell of the atom and which of them contains the last valence electrons, four groups of elements can be distinguished.
S-elements
These are those in which the s-orbital is the last to be filled. This family includes elements of the first group of the main subgroup (or Just one electron at the outer level determines the similar properties of these representatives as strong reducing agents.
P-elements
Only 30 pieces. Valence electrons are located at the p-sublevel. These are the elements that form the main subgroups from the third to the eighth group, belonging to periods 3,4,5,6. Among them, the properties include both metals and typical non-metallic elements.
d-elements and f-elements
These are transition metals from the 4th to 7th major periods. There are 32 elements in total. Simple substances can exhibit both acidic and basic properties (oxidizing and reducing). Also amphoteric, that is, dual.
The f-family includes lanthanides and actinides, in which the last electrons are located in f-orbitals.
Substances formed by elements: simple
Also, all classes of chemical elements can exist in the form of simple or complex compounds. Thus, simple ones are considered to be those that are formed from the same structure in different quantities. For example, O 2 is oxygen or dioxygen, and O 3 is ozone. This phenomenon is called allotropy.
Simple chemical elements that form compounds of the same name are characteristic of each representative of the periodic table. But not all of them are the same in their properties. So, there are simple substances, metals and non-metals. The first form the main subgroups with 1-3 groups and all the secondary subgroups in the table. Non-metals form the main subgroups of groups 4-7. The eighth main group includes special elements - noble or inert gases.
Among all the simple elements discovered to date, they are known for normal conditions 11 gases, 2 liquid substances (bromine and mercury), all the rest are solid.
Complex connections
These include everything that consists of two or more chemical elements. There are a lot of examples, because chemical compounds more than 2 million are known! These are salts, oxides, bases and acids, complex compounds, all organic substances.
Anyone who went to school remembers that one of the compulsory subjects to study was chemistry. You might like her, or you might not like her - it doesn't matter. And it is likely that much knowledge in this discipline has already been forgotten and is not used in life. However, everyone probably remembers D.I. Mendeleev’s table of chemical elements. For many, it has remained a multi-colored table, where certain letters are written in each square, indicating the names of chemical elements. But here we will not talk about chemistry as such, and describe hundreds chemical reactions and processes, but we’ll tell you how the periodic table appeared in the first place - this story will be interesting to any person, and indeed to all those who are hungry for interesting and useful information.
A little background
Back in 1668, the outstanding Irish chemist, physicist and theologian Robert Boyle published a book in which many myths about alchemy were debunked, and in which he discussed the need to search for indecomposable chemical elements. The scientist also gave a list of them, consisting of only 15 elements, but admitted the idea that there may be more elements. This became the starting point not only in the search for new elements, but also in their systematization.
A hundred years later, the French chemist Antoine Lavoisier compiled new list, which already included 35 elements. 23 of them were later found to be indecomposable. But the search for new elements continued by scientists around the world. AND main role The famous Russian chemist Dmitry Ivanovich Mendeleev played a role in this process - he was the first to put forward the hypothesis that there could be a relationship between the atomic mass of elements and their location in the system.
Thanks to painstaking work and comparison of chemical elements, Mendeleev was able to discover the connection between the elements, in which they can be one, and their properties are not something taken for granted, but represent a periodically repeating phenomenon. As a result, in February 1869, Mendeleev formulated the first periodic law, and already in March his report “Relationship of properties with the atomic weight of elements” was presented to the Russian Chemical Society by the historian of chemistry N. A. Menshutkin. Then, in the same year, Mendeleev’s publication was published in the journal “Zeitschrift fur Chemie” in Germany, and in 1871, another German journal “Annalen der Chemie” published a new extensive publication by the scientist dedicated to his discovery.
Creating the periodic table
By 1869, the main idea had already been formed by Mendeleev, and quite quickly. a short time, but for a long time he could not arrange it into any orderly system that clearly displays what’s what. In one of the conversations with his colleague A.A. Inostrantsev, he even said that he had everything already worked out in his head, but he couldn’t put everything into a table. After this, according to Mendeleev’s biographers, he began painstaking work on his table, which lasted three days without breaks for sleep. They tried all sorts of ways to organize elements into a table, and the work was also complicated by the fact that at that time science did not yet know about all the chemical elements. But, despite this, the table was still created, and the elements were systematized.
The legend of Mendeleev's dream
Many have heard the story that D.I. Mendeleev dreamed about his table. This version was actively disseminated by the aforementioned Mendeleev’s associate A. A. Inostrantsev as a funny story with which he entertained his students. He said that Dmitry Ivanovich went to bed and in a dream clearly saw his table, in which all the chemical elements were arranged in in the right order. After this, the students even joked that 40° vodka was discovered in the same way. But there were still real prerequisites for the story with sleep: as already mentioned, Mendeleev worked on the table without sleep or rest, and Inostrantsev once found him tired and exhausted. During the day, Mendeleev decided to take a short rest, and some time later, he woke up abruptly, immediately took a piece of paper and drew a ready-made table on it. But the scientist himself refuted this whole story with the dream, saying: “I’ve been thinking about it, maybe for twenty years, and you think: I was sitting and suddenly... it’s ready.” So the legend of the dream may be very attractive, but the creation of the table was only possible through hard work.
Further work
In the period from 1869 to 1871, Mendeleev developed the ideas of periodicity, which tended to science community. And one of the important stages of this process was the understanding that any element in the system should have, based on the totality of its properties in comparison with the properties of other elements. Based on this, and also relying on the results of research into changes in glass-forming oxides, the chemist was able to make corrections to the values of the atomic masses of some elements, including uranium, indium, beryllium and others.
Mendeleev, of course, wanted to quickly fill the empty cells that remained in the table, and in 1870 he predicted that chemical elements unknown to science would soon be discovered, the atomic masses and properties of which he was able to calculate. The first of these were gallium (discovered in 1875), scandium (discovered in 1879) and germanium (discovered in 1885). Then the forecasts continued to be realized, and eight more new elements were discovered, including: polonium (1898), rhenium (1925), technetium (1937), francium (1939) and astatine (1942-1943). By the way, in 1900, D.I. Mendeleev and the Scottish chemist William Ramsay came to the conclusion that the table should also include elements of group zero - until 1962 they were called inert gases, and after that - noble gases.
Organization of the periodic table
Chemical elements in D.I. Mendeleev’s table are arranged in rows, in accordance with the increase in their mass, and the length of the rows is selected so that the elements in them have similar properties. For example, noble gases such as radon, xenon, krypton, argon, neon and helium are difficult to react with other elements and also have low chemical reactivity, which is why they are located in the far right column. And the elements in the left column (potassium, sodium, lithium, etc.) react well with other elements, and the reactions themselves are explosive. Simply put, within each column, elements have similar properties that vary from one column to the next. All elements up to No. 92 are found in nature, and from No. 93 artificial elements begin, which can only be created in laboratory conditions.
In its original version, the periodic system was understood only as a reflection of the order existing in nature, and there were no explanations as to why everything should be this way. It was only when quantum mechanics appeared that the true meaning of the order of elements in the table became clear.
Lessons in the creative process
Speaking about what lessons of the creative process can be drawn from the entire history of the creation of D. I. Mendeleev’s periodic table, we can cite as an example the ideas of the English researcher in the field of creative thinking Graham Wallace and the French scientist Henri Poincaré. Let's give them briefly.
According to the studies of Poincaré (1908) and Graham Wallace (1926), there are four main stages of creative thinking:
- Preparation– the stage of formulating the main problem and the first attempts to solve it;
- Incubation– a stage during which there is a temporary distraction from the process, but work on finding a solution to the problem is carried out on a subconscious level;
- Insight– the stage at which the intuitive solution is located. Moreover, this solution can be found in a situation that is completely unrelated to the problem;
- Examination– the stage of testing and implementation of a solution, at which this solution is tested and its possible further development.
As we can see, in the process of creating his table, Mendeleev intuitively followed precisely these four stages. How effective this is can be judged by the results, i.e. by the fact that the table was created. And given that its creation was a huge step forward not only for chemical science, but also for all of humanity, the above four stages can be applied both to the implementation of small projects and to the implementation of global plans. The main thing to remember is that not a single discovery, not a single solution to a problem can be found on its own, no matter how much we want to see them in a dream and no matter how much we sleep. In order for something to work out, it doesn’t matter whether it’s creating a table of chemical elements or developing a new marketing plan, you need to have certain knowledge and skills, as well as skillfully use your potential and work hard.
We wish you success in your endeavors and successful implementation of your plans!
How to use the periodic table? For an uninitiated person, reading the periodic table is the same as for a gnome looking at the ancient runes of the elves. And the periodic table, by the way, if used correctly, can tell a lot about the world. In addition to serving you well during the exam, it is also simply irreplaceable when solving huge amount chemical and physical problems. But how to read it? Fortunately, today everyone can learn this art. In this article we will tell you how to understand the periodic table.
The periodic table of chemical elements (Mendeleev’s table) is a classification of chemical elements that establishes the relationship various properties elements from charge atomic nucleus.
History of the creation of the Table
Dmitry Ivanovich Mendeleev was not a simple chemist, if anyone thinks so. He was a chemist, physicist, geologist, metrologist, ecologist, economist, oil worker, aeronaut, instrument maker and teacher. During his life, the scientist managed to conduct a lot of fundamental research in various fields of knowledge. For example, it is widely believed that it was Mendeleev who calculated the ideal strength of vodka - 40 degrees. We don’t know how Mendeleev felt about vodka, but we know for sure that his dissertation on the topic “Discourse on the combination of alcohol with water” had nothing to do with vodka and considered alcohol concentrations from 70 degrees. With all the merits of the scientist, the discovery of the periodic law of chemical elements - one of them fundamental laws nature, brought him the widest fame.
There is a legend according to which a scientist dreamed of the periodic table, after which all he had to do was refine the idea that had appeared. But, if everything were so simple.. This version of the creation of the periodic table, apparently, is nothing more than a legend. When asked how the table was opened, Dmitry Ivanovich himself answered: “ I’ve been thinking about it for maybe twenty years, but you think: I was sitting there and suddenly... it’s done.”
In the mid-nineteenth century, attempts to arrange the known chemical elements (63 elements were known) were undertaken in parallel by several scientists. For example, in 1862, Alexandre Emile Chancourtois placed elements along a helix and noted cyclic repetition chemical properties. Chemist and musician John Alexander Newlands proposed his version of the periodic table in 1866. An interesting fact is that the scientist tried to discover some kind of mystical musical harmony in the arrangement of the elements. Among other attempts, there was also Mendeleev’s attempt, which was crowned with success.
In 1869, the first table diagram was published, and March 1, 1869 is considered the day the periodic law was opened. The essence of Mendeleev's discovery was that the properties of elements with increasing atomic mass do not change monotonically, but periodically. The first version of the table contained only 63 elements, but Mendeleev undertook a number of very non-standard solutions. So, he guessed to leave space in the table for still undiscovered elements, and also changed the atomic masses of some elements. The fundamental correctness of the law derived by Mendeleev was confirmed very soon, after the discovery of gallium, scandium and germanium, the existence of which was predicted by the scientist.
Modern view of the periodic table
Below is the table itself
Today, instead of atomic weight (atomic mass), the concept of atomic number (the number of protons in the nucleus) is used to order elements. The table contains 120 elements, which are arranged from left to right in order of increasing atomic number (number of protons)
The table columns represent so-called groups, and the rows represent periods. The table has 18 groups and 8 periods.
- The metallic properties of elements decrease when moving along a period from left to right, and increase in the opposite direction.
- The sizes of atoms decrease when moving from left to right along periods.
- As you move from top to bottom through the group, the reducing metal properties increase.
- Oxidizing and non-metallic properties increase when moving along a period from left to right I.
What do we learn about an element from the table? For example, let's take the third element in the table - lithium, and consider it in detail.
First of all, we see the element symbol itself and its name below it. In the upper left corner is the atomic number of the element, in which order the element is arranged in the table. The atomic number, as already mentioned, is equal to the number of protons in the nucleus. The number of positive protons is usually equal to the number of negative electrons in an atom (except in isotopes).
The atomic mass is indicated under the atomic number (in this version of the table). If we round the atomic mass to the nearest integer, we get what is called the mass number. The difference between the mass number and the atomic number gives the number of neutrons in the nucleus. Thus, the number of neutrons in a helium nucleus is two, and in lithium it is four.
Our course “Periodical Table for Dummies” has ended. In conclusion, we invite you to watch the thematic video, and we hope that the question of how to use the periodic table of Mendeleev has become more clear to you. We remind you what to study new item It is always more effective not alone, but with the help of an experienced mentor. That is why you should never forget about them, who will gladly share their knowledge and experience with you.
See also: List of chemical elements by atomic number and Alphabetical list of chemical elements Contents 1 Symbols used in this moment... Wikipedia
See also: List of chemical elements by atomic number and List of chemical elements by symbol Alphabetical list of chemical elements. Nitrogen N Actinium Ac Aluminum Al Americium Am Argon Ar Astatine At ... Wikipedia
The periodic system of chemical elements (Mendeleev's table) is a classification of chemical elements that establishes the dependence of various properties of elements on the charge of the atomic nucleus. The system is a graphic expression of the periodic law, ... ... Wikipedia
The periodic system of chemical elements (Mendeleev's table) is a classification of chemical elements that establishes the dependence of various properties of elements on the charge of the atomic nucleus. The system is a graphic expression of the periodic law, ... ... Wikipedia
The periodic system of chemical elements (Mendeleev's table) is a classification of chemical elements that establishes the dependence of various properties of elements on the charge of the atomic nucleus. The system is a graphic expression of the periodic law, ... ... Wikipedia
The periodic system of chemical elements (Mendeleev's table) is a classification of chemical elements that establishes the dependence of various properties of elements on the charge of the atomic nucleus. The system is a graphic expression of the periodic law, ... ... Wikipedia
Chemical elements (periodic table) classification of chemical elements, establishing the dependence of various properties of elements on the charge of the atomic nucleus. The system is a graphic expression of the periodic law established by Russian... ... Wikipedia
The periodic system of chemical elements (Mendeleev's table) is a classification of chemical elements that establishes the dependence of various properties of elements on the charge of the atomic nucleus. The system is a graphic expression of the periodic law, ... ... Wikipedia
The periodic system of chemical elements (Mendeleev's table) is a classification of chemical elements that establishes the dependence of various properties of elements on the charge of the atomic nucleus. The system is a graphic expression of the periodic law, ... ... Wikipedia
Books
- Japanese-English-Russian dictionary for installation of industrial equipment. About 8,000 terms, Popova I.S.. The dictionary is intended for a wide range of users and primarily for translators and technical specialists involved in the supply and implementation of industrial equipment from Japan or...
