Many people have heard about Dmitri Ivanovich Mendeleev and about the “Periodic law of changes in the properties of chemical elements by groups and series” discovered by him in the 19th century (1869) (the author’s name of the table is “Periodic system of elements by groups and series”).
The discovery of the table of periodic chemical elements was one of the important milestones in the history of the development of chemistry as a science. The pioneer of the table was the Russian scientist Dmitry Mendeleev. An extraordinary scientist with the broadest scientific horizons managed to combine all ideas about the nature of chemical elements into a single coherent concept.
Table opening history
By the middle of the 19th century, 63 chemical elements had been discovered, and scientists around the world have repeatedly attempted to combine all the existing elements into a single concept. The elements were proposed to be placed in ascending order of atomic mass and divided into groups according to the similarity of chemical properties.
In 1863, the chemist and musician John Alexander Newland proposed his theory, who proposed a layout of chemical elements similar to that discovered by Mendeleev, but the work of the scientist was not taken seriously by the scientific community due to the fact that the author was carried away by the search for harmony and the connection of music with chemistry.
In 1869, Mendeleev published his scheme of the periodic table in the journal of the Russian Chemical Society and sent out a notice of the discovery to the leading scientists of the world. In the future, the chemist repeatedly refined and improved the scheme until it acquired its familiar form.
The essence of Mendeleev's discovery is that with the growth of the atomic mass Chemical properties elements change not monotonously, but periodically. After a certain number of elements with different properties, the properties begin to repeat. Thus, potassium is similar to sodium, fluorine is similar to chlorine, and gold is similar to silver and copper.
In 1871, Mendeleev finally united the ideas into the Periodic Law. Scientists predicted the discovery of several new chemical elements and described their chemical properties. Subsequently, the chemist's calculations were fully confirmed - gallium, scandium and germanium fully corresponded to the properties that Mendeleev attributed to them.
But not everything is so simple and there is something we do not know.
Few people know that D. I. Mendeleev was one of the first world-famous Russian scientists of the late 19th century, who defended in world science the idea of ether as a universal substantial entity, who gave it fundamental scientific and applied significance in revealing the secrets of Being and to improve the economic life of the people.
There is an opinion that the periodic table of chemical elements officially taught in schools and universities is a fake. Mendeleev himself in his work entitled "An attempt at a chemical understanding of the world ether" gave a slightly different table.
The last time, in an undistorted form, the real Periodic Table saw the light in 1906 in St. Petersburg (textbook "Fundamentals of Chemistry", VIII edition).
The differences are visible: the zero group is moved to the 8th, and the element lighter than hydrogen, with which the table should begin and which is conventionally called Newtonium (ether), is generally excluded.
The same table is immortalized by the "BLOODY TYRANT" comrade. Stalin in St. Petersburg, Moskovsky Ave. 19. VNIIM them. D. I. Mendeleeva (All-Russian Research Institute of Metrology)
The monument-table The Periodic Table of Chemical Elements of D. I. Mendeleev was made with mosaics under the guidance of Professor of the Academy of Arts V. A. Frolov (architectural design of Krichevsky). The monument is based on a table from the last lifetime 8th edition (1906) of D. I. Mendeleev’s Fundamentals of Chemistry. Elements discovered during the life of D. I. Mendeleev are marked in red. Elements discovered from 1907 to 1934 , are marked in blue.
Why and how did it happen that we are so brazenly and openly lied to?
Place and role of the world ether in the true table of D. I. Mendeleev
Many people have heard about Dmitri Ivanovich Mendeleev and about the “Periodic law of changes in the properties of chemical elements by groups and series” discovered by him in the 19th century (1869) (the author’s name for the table is “The Periodic Table of Elements by Groups and Series”).
Many also heard that D.I. Mendeleev was the organizer and permanent leader (1869-1905) of the Russian public scientific association called the Russian Chemical Society (since 1872 - the Russian Physico-Chemical Society), which published the world-famous journal ZhRFKhO throughout its existence, right up to until the liquidation by the Academy of Sciences of the USSR in 1930 - both the Society and its journal.
But few of those who know that D. I. Mendeleev was one of the last world-famous Russian scientists of the late 19th century, who defended in world science the idea of ether as a universal substantial entity, who gave it fundamental scientific and applied significance in revealing secrets Being and to improve the economic life of people.
Even fewer of those who know that after the sudden (!!?) death of D. I. Mendeleev (01.27.1907), who was then recognized as an outstanding scientist by all scientific communities around the world except for the St. Petersburg Academy of Sciences alone, his main discovery is “Periodic law” was deliberately and everywhere falsified by world academic science.
And there are very few who know that all of the above is linked together by the thread of sacrificial service of the best representatives and bearers of the immortal Russian Physical Thought for the good of the peoples, for public benefit, despite the growing wave of irresponsibility in the upper strata of society of that time.
In essence, this dissertation is devoted to the comprehensive development of the last thesis, because in true science any neglect of essential factors always leads to false results.
The elements of the zero group begin each row of other elements, located on the left side of the Table, “... which is a strictly logical consequence of understanding the periodic law” - Mendeleev.
Particularly important and even exceptional in the sense of the periodic law, the place belongs to the element "x", - "Newtonius", - the world ether. And this special element should be located at the very beginning of the entire Table, in the so-called “zero group of the zero row”. Moreover, being a system-forming element (more precisely, a system-forming entity) of all elements of the Periodic Table, the world ether is a substantive argument for the entire variety of elements of the Periodic Table. The Table itself, in this regard, acts as a closed functional of this very argument.
Sources:
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PERIODIC TABLE OF MENDELEEV
The construction of Mendeleev's periodic table of chemical elements corresponds to the characteristic periods of number theory and orthogonal bases. Complementing Hadamard matrices with matrices of even and odd orders creates a structural basis of nested matrix elements: matrices of the first (Odin), second (Euler), third (Mersenne), fourth (Hadamard), and fifth (Fermat) orders.
It is easy to see that orders of magnitude 4 k Hadamard matrices correspond to inert elements with an atomic mass that is a multiple of four: helium 4, neon 20, argon 40 (39.948), etc., but also the foundations of life and digital technology: carbon 12, oxygen 16, silicon 28, germanium 72.
It seems that with Mersenne matrices of orders 4 k-1, on the contrary, everything active, poisonous, destructive and corrosive is connected. But these are also radioactive elements - sources of energy, and lead 207 (the end product, poisonous salts). Fluorine, of course, is 19. The orders of the Mersenne matrices correspond to a sequence of radioactive elements called the actinium series: uranium 235, plutonium 239 (an isotope that is a more powerful source atomic energy than uranium), etc. These are also alkali metals lithium 7, sodium 23 and potassium 39.
Gallium - atomic weight 68
Orders 4 k–2 Euler matrices (double Mersenne) corresponds to nitrogen 14 (atmospheric base). Table salt is formed by two "mersenne-like" atoms of sodium 23 and chlorine 35, together this combination is typical, just for Euler matrices. The more massive chlorine with a weight of 35.4 is a little short of the Hadamard dimension of 36. Common salt crystals: a cube (! ie, a meek character, Hadamars) and an octahedron (more defiant, this is undoubtedly Euler).
In atomic physics, the iron 56 - nickel 59 transition is the boundary between the elements that provide energy during the synthesis of a larger nucleus (hydrogen bomb) and decay (uranium bomb). The order 58 is famous for the fact that for it there are not only analogues of Hadamard matrices in the form of Belevich matrices with zeros on the diagonal, there are also no many weighted matrices for it - the nearest orthogonal W(58,53) has 5 zeros in each column and row (deep gap ).
In the series corresponding to the Fermat matrices and their substitutions of orders 4 k+1, costs 257 fermii by the will of fate. You can't say anything, an exact hit. Here is gold 197. Copper 64 (63.547) and silver 108 (107.868), symbols of electronics, apparently do not reach gold and correspond to more modest Hadamard matrices. Copper, with its atomic weight not far from 63, is chemically active - its green oxides are well known.
Boron crystals under high magnification
WITH golden ratio boron is connected - the atomic mass among all other elements is closest to 10 (more precisely, 10.8, the proximity of the atomic weight to odd numbers also affects). Boron is a fairly complex element. Bohr plays a confusing role in the history of life itself. The framework structure in its structures is much more complicated than in diamond. The unique type of chemical bond that allows boron to absorb any impurity is very poorly understood, although a large number of scientists have already received Nobel Prizes for research related to it. The shape of the boron crystal is an icosahedron, five triangles form a vertex.
Platinum Mystery. The fifth element is, without a doubt, noble metals such as gold. Suspension over Hadamard dimension 4 k, for 1 large.
The stable isotope uranium 238
Recall, however, that Fermat numbers are rare (the closest is 257). Native gold crystals have a shape close to a cube, but the pentagram also sparkles. Its closest neighbor, platinum, a noble metal, is less than 4 times less atomic weight away from gold 197. Platinum has an atomic weight not 193, but somewhat increased, 194 (the order of the Euler matrices). A trifle, but it brings her into the camp of a few more aggressive elements. It is worth remembering, in connection with its inertness (it dissolves, perhaps, in aqua regia), platinum is used as an active catalyst for chemical processes.
Spongy platinum ignites hydrogen at room temperature. The nature of platinum is not at all peaceful, iridium 192 behaves more quietly (a mixture of isotopes 191 and 193). It is more like copper, but with the weight and character of gold.
Between neon 20 and sodium 23 there is no element with an atomic weight of 22. Of course, atomic weights are an integral characteristic. But among isotopes, in turn, there is also a curious correlation of properties with the properties of numbers and the corresponding matrices of orthogonal bases. As nuclear fuel The most widely used isotope is uranium 235 (Mersenne matrix order), in which a self-sustaining chain nuclear reaction. In nature, this element occurs in the stable form uranium 238 (the order of the Euler matrices). There is no element with an atomic weight of 13. As for chaos, the limited number of stable elements of the periodic table and the difficulty of finding high-order level matrices due to the barrier seen in thirteenth-order matrices correlate.
Isotopes of chemical elements, island of stability
He drew on the work of Robert Boyle and Antoine Lavouzier. The first scientist advocated the search for indecomposable chemical elements. 15 of those Boyle listed back in 1668.
Lavuzier added 13 more to them, but a century later. The search dragged on because there was no coherent theory of the connection between the elements. Finally, Dmitry Mendeleev entered the "game". He decided that there is a connection between the atomic mass of substances and their place in the system.
This theory allowed the scientist to discover dozens of elements without discovering them in practice, but in nature. This was placed on the shoulders of posterity. But now it's not about them. Let's dedicate the article to the great Russian scientist and his table.
The history of the creation of the periodic table
Mendeleev table began with the book "Relationship of properties with the atomic weight of the elements." The work was issued in the 1870s. At the same time, the Russian scientist spoke to the chemical society of the country and sent the first version of the table to colleagues from abroad.
Before Mendeleev, 63 elements were discovered by various scientists. Our compatriot began by comparing their properties. First of all, he worked with potassium and chlorine. Then, he took up the group of metals of the alkaline group.
The chemist got a special table and element cards to lay them out like solitaire, looking for the right matches and combinations. As a result, an insight came: - the properties of the components depend on the mass of their atoms. So, elements of the periodic table lined up in ranks.
The discovery of the maestro of chemistry was the decision to leave voids in these ranks. The periodicity of the difference between atomic masses led the scientist to assume that not all elements are known to mankind yet. The gaps in weight between some of the "neighbors" were too large.
That's why, periodic table of Mendeleev became like a chessboard, with an abundance of "white" cells. Time has shown that they really were waiting for their "guests". They, for example, became inert gases. Helium, neon, argon, krypton, radioact and xenon were discovered only in the 30s of the 20th century.
Now about myths. It is widely believed that periodic table of chemistry appeared to him in a dream. These are the intrigues of university teachers, more precisely, one of them - Alexander Inostrantsev. This is a Russian geologist who lectured at the St. Petersburg University of Mining.
Inostrantsev knew Mendeleev and visited him. Once, exhausted by the search, Dmitry fell asleep right in front of Alexander. He waited until the chemist wakes up and saw how Mendeleev grabs a piece of paper and writes down the final version of the table.
In fact, the scientist simply did not have time to do this before Morpheus captured him. However, Inostrantsev wanted to amuse his students. Based on what he saw, the geologist came up with a bike, which grateful listeners quickly spread to the masses.
Features of the periodic table
Since the first version in 1969 ordinal periodic table improved many times. So, with the discovery of noble gases in the 1930s, it was possible to derive a new dependence of the elements - on their serial numbers, and not on the mass, as the author of the system stated.
The concept of "atomic weight" was replaced by "atomic number". It was possible to study the number of protons in the nuclei of atoms. This number is the serial number of the element.
Scientists of the 20th century also studied the electronic structure of atoms. It also affects the periodicity of elements and is reflected in later editions. periodic tables. Photo The list shows that the substances in it are arranged as the atomic weight increases.
The fundamental principle was not changed. Mass increases from left to right. At the same time, the table is not single, but divided into 7 periods. Hence the name of the list. Period is a horizontal row. Its beginning is typical metals, the end is elements with non-metallic properties. The decline is gradual.
There are big and small periods. The first ones are at the beginning of the table, there are 3 of them. It opens a list with a period of 2 elements. Following are two columns, in which there are 8 items. The remaining 4 periods are large. The 6th is the longest, it has 32 elements. In the 4th and 5th there are 18 of them, and in the 7th - 24.
Can be counted how many elements in the table Mendeleev. There are 112 titles in total. Names. There are 118 cells, but there are variations of the list with 126 fields. There are still empty cells for undiscovered elements that do not have names.
Not all periods fit on one line. Large periods consist of 2 rows. The amount of metals in them outweighs. Therefore, the bottom lines are completely devoted to them. A gradual decrease from metals to inert substances is observed in the upper rows.
Pictures of periodic table divided vertically. This groups in the periodic table, there are 8 of them. Elements similar in chemical properties are arranged vertically. They are divided into main and secondary subgroups. The latter begin only from the 4th period. The main subgroups also include elements of small periods.
The essence of the periodic table
Names of elements in the periodic table is 112 positions. The essence of their arrangement in a single list is the systematization of primary elements. They began to fight over this even in ancient times.
Aristotle was one of the first to understand what everything that exists was made of. He took as a basis the properties of substances - cold and heat. Empidocles singled out 4 fundamental principles according to the elements: water, earth, fire and air.
Metals in the periodic table, like other elements, are the very fundamental principles, but from a modern point of view. The Russian chemist managed to discover most of the components of our world and to suggest the existence of still unknown primary elements.
It turns out that pronunciation of the periodic table- voicing a certain model of our reality, decomposing it into components. However, learning them is not easy. Let's try to make the task easier by describing a couple of effective methods.
How to learn the periodic table
Let's start with the modern method. Computer scientists have developed a number of flash games that help memorize Mendeleev's list. Project participants are offered to find elements by different options, for example, name, atomic mass, letter designation.
The player has the right to choose the field of activity - only part of the table, or all of it. In our will, also, exclude the names of elements, other parameters. This complicates the search. For the advanced, a timer is also provided, that is, training is carried out at speed.
Game conditions make learning element numbers in the periodic table not boring, but entertaining. Excitement wakes up, and it becomes easier to systematize knowledge in the head. Those who do not accept computer flash projects offer a more traditional way of memorizing a list.
It is divided into 8 groups, or 18 (according to the 1989 edition). For ease of remembering, it is better to create several separate tables, rather than working on a whole version. Visual images matched to each of the elements also help. Rely on your own associations.
So, iron in the brain can be correlated, for example, with a nail, and mercury with a thermometer. The name of the element is unfamiliar? We use the method of suggestive associations. , for example, we will compose from the beginnings of the words "taffy" and "speaker".
Characteristics of the periodic table don't study in one sitting. Lessons are recommended for 10-20 minutes a day. It is recommended to start by remembering only the basic characteristics: the name of the element, its designation, atomic mass and serial number.
Schoolchildren prefer to hang the periodic table above the desktop, or on the wall, which is often looked at. The method is good for people with a predominance of visual memory. Data from the list is involuntarily remembered even without cramming.
This is also taken into account by teachers. As a rule, they do not force you to memorize the list, they allow you to look at it even on the control ones. Constantly looking at the table is tantamount to the effect of printing on the wall, or writing cheat sheets before exams.
Starting the study, let us recall that Mendeleev did not immediately remember his list. Once, when the scientist was asked how he opened the table, the answer was: “I’ve been thinking about it for maybe 20 years, but you think: I sat and, suddenly, it’s ready.” The periodic system is painstaking work that cannot be mastered in a short time.
Science does not tolerate haste, because it leads to delusions and annoying mistakes. So, at the same time as Mendeleev, the table was compiled by Lothar Meyer. However, the German did not finish the list a bit and was not convincing in proving his point of view. Therefore, the public recognized the work of the Russian scientist, and not his fellow chemist from Germany.
The periodic system of chemical elements is a classification of chemical elements created by D. I. Mendeleev on the basis of the periodic law discovered by him in 1869.
D. I. Mendeleev
According to the modern formulation of this law, in a continuous series of elements arranged in ascending order of the positive charge of the nuclei of their atoms, elements with similar properties are periodically repeated.
The periodic system of chemical elements, presented in the form of a table, consists of periods, series and groups.
At the beginning of each period (with the exception of the first) there is an element with pronounced metallic properties (alkali metal).
Symbols for the color table: 1 - chemical sign of the element; 2 - name; 3 - atomic mass (atomic weight); 4 - serial number; 5 - distribution of electrons over the layers.
As the ordinal number of the element increases, equal to the value of the positive charge of the nucleus of its atom, the metallic properties gradually weaken and the non-metallic properties increase. The penultimate element in each period is an element with pronounced non-metallic properties (), and the last is an inert gas. In period I there are 2 elements, in II and III - 8 elements each, in IV and V - 18 elements each, in VI - 32 and in VII (incomplete period) - 17 elements.
The first three periods are called small periods, each of them consists of one horizontal row; the rest - in large periods, each of which (excluding the VII period) consists of two horizontal rows - even (upper) and odd (lower). In even rows of large periods are only metals. The properties of the elements in these rows change slightly with increasing serial number. The properties of elements in odd series of large periods change. In period VI, lanthanum is followed by 14 elements that are very similar in chemical properties. These elements, called lanthanides, are listed separately under the main table. Actinides, the elements following actinium, are similarly presented in the table.
The table has nine vertical groups. The group number, with rare exceptions, is equal to the highest positive valence of the elements of this group. Each group, excluding zero and eighth, is divided into subgroups. - main (located to the right) and side. In the main subgroups, with an increase in the serial number, the metallic properties of the elements are enhanced and the non-metallic properties of the elements are weakened.
Thus, chemical and series physical properties elements are determined by the place that a given element occupies in the periodic system.
Biogenic elements, i.e., elements that make up organisms and perform a certain biological role in it, occupy the upper part of the periodic table. The cells occupied by the elements that make up the bulk (more than 99%) of living matter are colored blue, the cells occupied by microelements are colored pink (see).
The periodic system of chemical elements is the greatest achievement of modern natural science and a vivid expression of the most general dialectical laws of nature.
See also , Atomic weight.
The periodic system of chemical elements is a natural classification of chemical elements created by D. I. Mendeleev on the basis of the periodic law discovered by him in 1869.
In the original formulation, the periodic law of D. I. Mendeleev stated: the properties of chemical elements, as well as the forms and properties of their compounds, are in a periodic dependence on the magnitude of the atomic weights of the elements. Later, with the development of the theory of the structure of the atom, it was shown that more accurate characterization of each element is not the atomic weight (see), but the value of the positive charge of the nucleus of the atom of the element, equal to the ordinal (atomic) number of this element in the periodic system of D. I. Mendeleev. The number of positive charges on the nucleus of an atom is equal to the number of electrons surrounding the nucleus of an atom, since atoms as a whole are electrically neutral. In the light of these data, the periodic law is formulated as follows: the properties of chemical elements, as well as the forms and properties of their compounds, are in a periodic dependence on the positive charge of the nuclei of their atoms. This means that in a continuous series of elements, arranged in ascending order of the positive charges of the nuclei of their atoms, elements with similar properties will be periodically repeated.
The tabular form of the periodic system of chemical elements is presented in its modern form. It consists of periods, series and groups. A period represents a sequential horizontal row of elements arranged in ascending order of the positive charge of the nuclei of their atoms.
At the beginning of each period (with the exception of the first) there is an element with pronounced metallic properties (alkali metal). Then, as the serial number increases, the metallic properties of the elements gradually weaken and the non-metallic properties of the elements increase. The penultimate element in each period is an element with pronounced non-metallic properties (halogen), and the last is an inert gas. I period consists of two elements, the role alkali metal and halogen is simultaneously performed by hydrogen. II and III periods include 8 elements each, called Mendeleev typical. IV and V periods have 18 elements each, VI-32. VII period is not yet completed and is replenished with artificially created elements; there are currently 17 elements in this period. I, II and III periods are called small, each of them consists of one horizontal row, IV-VII - large: they (with the exception of VII) include two horizontal rows - even (upper) and odd (lower). In even rows of large periods, only metals are found, and the change in the properties of the elements in the row from left to right is weakly expressed.
In odd series of large periods, the properties of the elements in the series change in the same way as the properties of typical elements. In an even number of the VI period after lanthanum 14 elements follow [called lanthanides (see), lanthanides, rare earth elements], similar in chemical properties to lanthanum and to each other. Their list is given separately under the table.
Separately, the elements following the actinium-actinides (actinides) are written out and given under the table.
There are nine vertical groups in the periodic table of chemical elements. The group number is equal to the highest positive valency (see) of the elements of this group. The exceptions are fluorine (it happens only negatively monovalent) and bromine (it does not happen heptavalent); in addition, copper, silver, gold can exhibit a valence greater than +1 (Cu-1 and 2, Ag and Au-1 and 3), and of the elements of group VIII, only osmium and ruthenium have a valence of +8. Each group, with the exception of the eighth and zero, is divided into two subgroups: the main (located to the right) and the secondary. The main subgroups include typical elements and elements of large periods, the secondary - only elements of large periods and, moreover, metals.
In terms of chemical properties, the elements of each subgroup of this group differ significantly from each other, and only the highest positive valency is the same for all elements of this group. In the main subgroups, from top to bottom, the metallic properties of elements increase and non-metallic ones weaken (for example, francium is an element with the most pronounced metallic properties, and fluorine is non-metallic). Thus, the place of an element in the periodic system of Mendeleev (serial number) determines its properties, which are the average of the properties of neighboring elements vertically and horizontally.
Some groups of elements have special names. So, the elements of the main subgroups of group I are called alkali metals, group II - alkaline earth metals, group VII - halogens, elements located behind uranium - transuranium. Elements that are part of organisms, take part in metabolic processes and have a pronounced biological role, are called biogenic elements. All of them occupy the upper part of the table of D. I. Mendeleev. This is primarily O, C, H, N, Ca, P, K, S, Na, Cl, Mg and Fe, which make up the bulk of living matter (more than 99%). The places occupied by these elements in the periodic table are colored in light blue. Biogenic elements, which are very few in the body (from 10 -3 to 10 -14%), are called microelements (see). In the cells of the periodic system, colored yellow, microelements are placed, the vital importance of which for humans has been proven.
According to the theory of the structure of atoms (see Atom), the chemical properties of elements depend mainly on the number of electrons in the outer electron shell. The periodic change in the properties of elements with an increase in the positive charge of atomic nuclei is explained by the periodic repetition of the structure of the outer electron shell ( energy level) atoms.
In small periods, with an increase in the positive charge of the nucleus, the number of electrons in the outer shell increases from 1 to 2 in period I and from 1 to 8 in periods II and III. Hence the change in the properties of the elements in the period from an alkali metal to an inert gas. The outer electron shell, containing 8 electrons, is complete and energetically stable (elements of the zero group are chemically inert).
In large periods in even rows, with an increase in the positive charge of the nuclei, the number of electrons in the outer shell remains constant (1 or 2) and the second outer shell is filled with electrons. Hence the slow change in the properties of elements in even rows. In odd series of long periods, with an increase in the charge of the nuclei, the outer shell is filled with electrons (from 1 to 8) and the properties of the elements change in the same way as for typical elements.
The number of electron shells in an atom is equal to the period number. The atoms of the elements of the main subgroups have a number of electrons on their outer shells equal to the group number. The atoms of the elements of the secondary subgroups contain one or two electrons on the outer shells. This explains the difference in the properties of the elements of the main and secondary subgroups. The group number indicates the possible number of electrons that can participate in the formation of chemical (valence) bonds (see Molecule), therefore such electrons are called valence. For elements of secondary subgroups, not only the electrons of the outer shells, but also the penultimate ones, are valence. The number and structure of electron shells are indicated in the attached periodic table of chemical elements.
The periodic law of D. I. Mendeleev and the system based on it are of exceptionally great importance in science and practice. The periodic law and the system were the basis for the discovery of new chemical elements, the accurate determination of their atomic weights, the development of the theory of the structure of atoms, the establishment of geochemical laws for the distribution of elements in the earth's crust and the development of modern ideas about living matter, the composition of which and the laws associated with it are in accordance with the periodic system. Biological activity elements and their content in the body are also largely determined by the place they occupy in the periodic system of Mendeleev. So, with an increase in the serial number in a number of groups, the toxicity of elements increases and their content in the body decreases. The periodic law is a vivid expression of the most general dialectical laws of the development of nature.
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