Periodic table how chemical elements are read. Names of chemical elements

How to use the periodic table? For an uninitiated person, reading the periodic table is the same as looking at the ancient runes of elves for a dwarf. And the periodic table can tell a lot about the world.

In addition to serving you in the exam, it is also simply indispensable for solving a huge number of 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 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.

History of the creation of the Table

Dmitri Ivanovich Mendeleev was not a simple chemist, if someone thinks so. He was a chemist, physicist, geologist, metrologist, ecologist, economist, oilman, 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 do not know how Mendeleev treated vodka, but it is known 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 the fundamental laws of nature, brought him the widest fame.

There is a legend according to which the scientist dreamed of the periodic system, after which he only had to finalize 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, and you think: I sat and suddenly ... it’s ready. ”

In the middle of the nineteenth century, attempts to streamline the known chemical elements (63 elements were known) were simultaneously undertaken by several scientists. For example, in 1862 Alexandre Émile Chancourtois placed the elements along a helix and noted the cyclical repetition of chemical properties.

Chemist and musician John Alexander Newlands proposed his version of the periodic table in 1866. An interesting fact is that in the arrangement of the elements the scientist tried to discover some mystical musical harmony. Among other attempts was the attempt of Mendeleev, which was crowned with success.

In 1869, the first scheme of the table was published, and the day of March 1, 1869 is considered the day of the discovery of the periodic law. The essence of Mendeleev's discovery was that the properties of elements with increasing atomic mass do not change monotonously, but periodically.

The first version of the table contained only 63 elements, but Mendeleev made a number of very non-standard decisions. So, he guessed to leave a place in the table for yet 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 scientists.

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 ascending order of atomic number (number of protons)

The columns of the table are so-called groups, and the rows are periods. There are 18 groups and 8 periods in the table.

1. The metallic properties of elements decrease when moving along the period from left to right, and increase in the opposite direction.
2. The dimensions of atoms decrease as they move from left to right along the periods.
3. When moving from top to bottom in the group, the reducing metallic properties increase.
4. Oxidizing and non-metallic properties increase along the period from left to right.

What do we learn about the 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 symbol of the element itself and its name under it. In the upper left corner is the atomic number of the element, in the order in which the element is located 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 (with the exception of 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 the so-called 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 - four.

So our course "Mendeleev's Table for Dummies" has ended. In conclusion, we invite you to watch a 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 that learning a new subject is always more effective not alone, but with the help of an experienced mentor. That is why, you should never forget about the student service, which will gladly share their knowledge and experience with you.

After oxygen silicon is the most abundant element in the earth's crust. It has 2 stable isotopes: 28 Si, 29 Si, 30 Si. Silicon is not found in free form in nature.

The most common are: salts of silicic acids and silicon oxide (silica, sand, quartz). They are part of mineral salts, mica, talc, asbestos.

Allotropy of silicon.

At silicon There are 2 allotropic modifications:

Crystalline (light gray crystals. The structure is similar to the crystal lattice of diamond, where the silicon atom is covalently bonded to 4 identical atoms, and is itself in sp3 - hybridization);

Amorphous (brown powder, more active form than crystalline).

silicon properties.

At temperature, silicon reacts with atmospheric oxygen:

Si + O 2 = SiO 2 .

If there is not enough oxygen (lack), then the following reaction may take place:

2 Si + O 2 = 2 SiO,

Where SiO- monoxide, which can also be formed during the reaction:

Si + SiO 2 = 2 SiO.

Under normal conditions silicon may react with F 2 , when heated - with Cl 2 . If the temperature is increased further, then Si will be able to interact with N And S:

4Si + S 8 = 4SiS 2;

Si + 2F 2 \u003d SiF 4.

Silicon is able to react with carbon, giving carborundum:

Si + C = SiC.

Silicon is soluble in a mixture of concentrated nitric and hydrofluoric acids:

3Si + 4HNO 3 + 12HF = 3SiF 4 + 4NO + 8H 2 O.

Silicon dissolves in aqueous solutions of alkalis:

Si + 2NaOH + H 2 O \u003d Na 2 SiO 3 + H 2.

When heated with oxides, silicon disproportionates:

2 MgO + 3 Si = mg 2 Si + 2 SiO.

When interacting with metals, silicon acts as an oxidizing agent:

2 mg + Si = mg 2 Si.

Application of silicon.

Silicon finds the greatest use in the production of alloys for giving strength to aluminum, copper and magnesium and for the production of ferrosilicides, which are important in the production of steels and semiconductor technology. Silicon crystals are used in solar cells and semiconductor devices - transistors and diodes.

Silicon also serves as a raw material for the production of organosilicon compounds, or siloxanes, obtained in the form of oils, lubricants, plastics and synthetic rubbers. Inorganic silicon compounds are used in ceramic and glass technology as an insulating material and piezocrystals.

One of the most common elements in nature is silicium, or silicon. Such a wide distribution speaks of the importance and significance of this substance. This was quickly understood and adopted by people who learned how to properly use silicon for their own purposes. Its application is based on special properties, which we will talk about later.

Silicon - chemical element

If we characterize this element by position in the periodic system, then we can identify the following important points:

1. The serial number is 14.
2. The period is the third small.
3. Group - IV.
4. The subgroup is the main one.
5. The structure of the outer electron shell is expressed by the formula 3s 2 3p 2 .
6. The element silicon is represented by the chemical symbol Si, which is pronounced "silicium".
7. The oxidation states it exhibits are: -4; +2; +4.
8. The valence of an atom is IV.
9. The atomic mass of silicon is 28.086.
10. In nature, there are three stable isotopes of this element with mass numbers 28, 29 and 30.

Thus, from a chemical point of view, the silicon atom is a sufficiently studied element, many of its various properties have been described.

Discovery history

Since various compounds of the element under consideration are very popular and massive in content in nature, from ancient times people used and knew about the properties of just many of them. Pure silicon for a long time remained beyond the knowledge of man in chemistry.

The most popular compounds used in everyday life and industry by the peoples of ancient cultures (Egyptians, Romans, Chinese, Russians, Persians and others) were precious and ornamental stones based on silicon oxide. These include:

• opal;
• rhinestone;
• topaz;
• chrysoprase;
• onyx;
• chalcedony and others.

Since ancient times, it has been customary to use quartz in the construction business. However, elemental silicon itself remained undiscovered until the 19th century, although many scientists tried in vain to isolate it from various compounds, using catalysts, high temperatures, and even electric current. These are such bright minds as:

• Carl Scheele;
• Gay-Lussac;
• Thenar;
• Humphrey Davy;
• Antoine Lavoisier.

Jens Jacobs Berzelius succeeded in obtaining pure silicon in 1823. To do this, he conducted an experiment on the fusion of vapors of silicon fluoride and metallic potassium. As a result, he received an amorphous modification of the element in question. The same scientist proposed a Latin name for the discovered atom.

A little later, in 1855, another scientist - Saint Clair-Deville - managed to synthesize another allotropic variety - crystalline silicon. Since then, knowledge about this element and its properties began to grow very quickly. People realized that it has unique features that can be very intelligently used to meet their own needs. Therefore, today one of the most demanded elements in electronics and technology is silicon. Its application only expands its boundaries every year.

The Russian name for the atom was given by the scientist Hess in 1831. That is what has stuck to this day.

Silicon is the second most abundant in nature after oxygen. Its percentage in comparison with other atoms in the composition of the earth's crust is 29.5%. In addition, carbon and silicon are two special elements that can form chains by connecting with each other. That is why more than 400 different natural minerals are known for the latter, in the composition of which it is contained in the lithosphere, hydrosphere and biomass.

Where exactly is silicon found?

1. In deep layers of soil.
2. In rocks, deposits and massifs.
3. At the bottom of water bodies, especially seas and oceans.
4. In plants and marine inhabitants of the animal kingdom.
5. In humans and land animals.

It is possible to designate several of the most common minerals and rocks, in which silicon is present in large quantities. Their chemistry is such that the mass content of a pure element in them reaches 75%. However, the specific figure depends on the type of material. So, rocks and minerals containing silicon:

• feldspars;
• mica;
• amphiboles;
• opals;
• chalcedony;
• silicates;
• sandstones;
• aluminosilicates;
• clay and others.

Accumulating in the shells and external skeletons of marine animals, silicon eventually forms powerful deposits of silica at the bottom of water bodies. This is one of the natural sources of this element.

In addition, it was found that silicium can exist in a pure native form - in the form of crystals. But such deposits are very rare.

Physical properties of silicon

If we characterize the element under consideration by a set of physicochemical properties, then first of all, it is the physical parameters that should be designated. Here are a few main ones:

1. It exists in the form of two allotropic modifications - amorphous and crystalline, which differ in all properties.
2. The crystal lattice is very similar to that of diamond, because carbon and silicon are almost the same in this respect. However, the distance between the atoms is different (silicon has more), so the diamond is much harder and stronger. Lattice type - cubic face-centered.
3. The substance is very brittle, at high temperatures it becomes plastic.
4. The melting point is 1415˚С.
5. Boiling point - 3250˚С.
6. The density of the substance is 2.33 g / cm 3.
7. The color of the compound is silver-gray, a characteristic metallic sheen is expressed.
8. It has good semiconductor properties, which can vary with the addition of certain agents.
9. Insoluble in water, organic solvents and acids.
10. Specifically soluble in alkalis.

The designated physical properties of silicon allow people to control it and use it to create various products. For example, the use of pure silicon in electronics is based on the properties of semiconductivity.

Chemical properties

The chemical properties of silicon are highly dependent on the reaction conditions. If we talk about at standard parameters, then we need to designate a very low activity. Both crystalline and amorphous silicon are very inert. They do not interact with strong oxidizing agents (except fluorine) or with strong reducing agents.

This is due to the fact that an oxide film of SiO 2 is instantly formed on the surface of the substance, which prevents further interactions. It can be formed under the influence of water, air, vapors.

If, however, the standard conditions are changed and silicon is heated to a temperature above 400˚С, then its chemical activity will greatly increase. In this case, it will react with:

• oxygen;
• all kinds of halogens;
• hydrogen.

With a further increase in temperature, the formation of products upon interaction with boron, nitrogen, and carbon is possible. Of particular importance is carborundum - SiC, as it is a good abrasive material.

Also, the chemical properties of silicon are clearly seen in reactions with metals. In relation to them, it is an oxidizing agent, therefore the products are called silicides. Similar compounds are known for:

• alkaline;
• alkaline earth;
• transition metals.

The compound obtained by fusing iron and silicon has unusual properties. It is called ferrosilicon ceramics and is successfully used in industry.

Silicon does not interact with complex substances, therefore, of all their varieties, it can dissolve only in:

• aqua regia (a mixture of nitric and hydrochloric acids);
• caustic alkalis.

In this case, the temperature of the solution should be at least 60 ° C. All this once again confirms the physical basis of the substance - a diamond-like stable crystal lattice, which gives it strength and inertness.

How to get

Obtaining silicon in its pure form is a rather costly process economically. In addition, due to its properties, any method gives only 90-99% pure product, while impurities in the form of metals and carbon remain the same. So just getting the substance is not enough. It should also be qualitatively cleaned of foreign elements.

In general, the production of silicon is carried out in two main ways:

1. From white sand, which is pure silicon oxide SiO 2 . When it is calcined with active metals (most often with magnesium), a free element is formed in the form of an amorphous modification. The purity of this method is high, the product is obtained with a 99.9 percent yield.
2. A more widespread method on an industrial scale is the sintering of molten sand with coke in specialized thermal kilns. This method was developed by the Russian scientist N. N. Beketov.

Further processing consists in subjecting the products to purification methods. For this, acids or halogens (chlorine, fluorine) are used.

Amorphous silicon

The characterization of silicon will be incomplete if each of its allotropic modifications is not considered separately. The first one is amorphous. In this state, the substance we are considering is a brown-brown powder, finely dispersed. It has a high degree of hygroscopicity, exhibits a sufficiently high chemical activity when heated. Under standard conditions, it is able to interact only with the strongest oxidizing agent - fluorine.

Calling amorphous silicon just a kind of crystalline is not entirely correct. Its lattice shows that this substance is only a form of finely dispersed silicon that exists in the form of crystals. Therefore, as such, these modifications are one and the same compound.

However, their properties differ, and therefore it is customary to speak of allotropy. By itself, amorphous silicon has a high light absorption capacity. In addition, under certain conditions, this indicator is several times higher than that of the crystalline form. Therefore, it is used for technical purposes. In the considered form (powder), the compound is easily applied to any surface, be it plastic or glass. Therefore, it is amorphous silicon that is so convenient for use. The application is based on different sizes.

Although the wear of batteries of this type is quite fast, which is associated with abrasion of a thin film of the substance, however, the use and demand is only growing. Indeed, even in a short service life, solar cells based on amorphous silicon are able to provide energy to entire enterprises. In addition, the production of such a substance is waste-free, which makes it very economical.

This modification is obtained by reducing compounds with active metals, for example, sodium or magnesium.

Crystalline silicon

Silver-gray shiny modification of the element in question. It is this form that is the most common and most in demand. This is due to the set of qualitative properties that this substance possesses.

The characteristic of silicon with a crystal lattice includes a classification of its types, since there are several of them:

1. Electronic quality - the purest and highest quality. It is this type that is used in electronics to create especially sensitive devices.
2. Solar quality. The name itself defines the area of ​​use. It is also a high-purity silicon, the use of which is necessary to create high-quality and long-lasting solar cells. Photovoltaic converters created on the basis of a crystalline structure are of higher quality and wear resistance than those created using an amorphous modification by deposition on various types of substrates.
3. Technical silicon. This variety includes those samples of a substance that contain about 98% of the pure element. Everything else goes to various kinds of impurities:

• aluminum;
• chlorine;
• carbon;
• phosphorus and others.

The last variety of the substance under consideration is used to obtain silicon polycrystals. For this, recrystallization processes are carried out. As a result, in terms of purity, products are obtained that can be attributed to the groups of solar and electronic quality.

By its nature, polysilicon is an intermediate product between the amorphous modification and the crystalline one. This option is easier to work with, it is better processed and cleaned with fluorine and chlorine.

The resulting products can be classified as follows:

• multisilicon;
• monocrystalline;
• profiled crystals;
• silicon scrap;
• technical silicon;
• production waste in the form of fragments and scraps of matter.

Each of them finds application in industry and is used by a person completely. Therefore, those related to silicon are considered waste-free. This significantly reduces its economic cost, without affecting the quality.

The use of pure silicon

Silicon production in the industry is established quite well, and its scale is quite voluminous. This is due to the fact that this element, both pure and in the form of various compounds, is widespread and in demand in various branches of science and technology.

Where is crystalline and amorphous silicon used in its pure form?

1. In metallurgy as an alloying additive capable of changing the properties of metals and their alloys. So, it is used in the smelting of steel and iron.
2. Different types of substances are used to produce a cleaner version - polysilicon.
3. Silicon compounds with are a whole chemical industry that has gained particular popularity today. Silicone materials are used in medicine, in the manufacture of dishes, tools and much more.
4. Manufacture of various solar panels. This method of obtaining energy is one of the most promising in the future. Environmentally friendly, cost-effective and durable - the main advantages of such electricity production.
5. Silicon for lighters has been used for a very long time. Even in ancient times, people used flint to create a spark when lighting a fire. This principle is the basis for the production of lighters of various kinds. Today there are species in which flint is replaced by an alloy of a certain composition, which gives an even faster result (sparking).
6. Electronics and solar energy.
7. Manufacture of mirrors in gas laser devices.

Thus, pure silicon has a lot of advantageous and special properties that allow it to be used to create important and necessary products.

The use of silicon compounds

In addition to a simple substance, various silicon compounds are also used, and very widely. There is a whole branch of industry called silicate. It is she who is based on the use of various substances, which include this amazing element. What are these compounds and what is produced from them?

1. Quartz, or river sand - SiO 2. It is used for the manufacture of building and decorative materials such as cement and glass. Where these materials are used, everyone knows. No construction is complete without these components, which confirms the importance of silicon compounds.
2. Silicate ceramics, which includes materials such as faience, porcelain, brick and products based on them. These components are used in medicine, in the manufacture of dishes, decorative ornaments, household items, in construction and other household areas of human activity.
3. - silicones, silica gels, silicone oils.
4. Silicate glue - used as stationery, in pyrotechnics and construction.

Silicon, the price of which varies on the world market, but does not cross the mark of 100 Russian rubles per kilogram (per crystalline) from top to bottom, is a sought-after and valuable substance. Naturally, compounds of this element are also widespread and applicable.

The biological role of silicon

From the point of view of significance for the body, silicon is important. Its content and distribution in tissues is as follows:

• 0.002% - muscle;
• 0.000017% - bone;
• blood - 3.9 mg / l.

Every day, about one gram of silicon should get inside, otherwise diseases will begin to develop. There are no deadly ones among them, however, prolonged silicon starvation leads to:

• hair loss;
• the appearance of acne and pimples;
• fragility and fragility of bones;
• easy capillary permeability;
• fatigue and headaches;
• the appearance of numerous bruises and bruises.

For plants, silicon is an important trace element necessary for normal growth and development. Animal experiments have shown that those individuals that consume a sufficient amount of silicon daily grow better.

As an independent chemical element, silicon became known to mankind only in 1825. Which, of course, did not prevent the use of silicon compounds in such a number of spheres that it is easier to list those where the element is not used. This article will shed light on the physical, mechanical and useful chemical properties of silicon and its compounds, applications, and we will also talk about how silicon affects the properties of steel and other metals.

To begin with, let's dwell on the general characteristics of silicon. From 27.6 to 29.5% of the mass of the earth's crust is silicon. In sea water, the concentration of the element is also fair - up to 3 mg / l.

In terms of prevalence in the lithosphere, silicon occupies the second place of honor after oxygen. However, its most well-known form, silica, is an oxide, and it is precisely its properties that have become the basis for such a wide application.

This video will tell you what silicon is:

Concept and features

Silicon is a non-metal, but under different conditions it can exhibit both acidic and basic properties. It is a typical semiconductor and is extremely widely used in electrical engineering. Its physical and chemical properties are largely determined by the allotropic state. Most often, they deal with the crystalline form, since its qualities are more in demand in the national economy.

• Silicon is one of the basic macronutrients in the human body. Its lack has a detrimental effect on the condition of bone tissue, hair, skin, nails. In addition, silicon affects the performance of the immune system.
• In medicine, the element, or rather, its compounds, found their first use in this capacity. Water from wells lined with flint was not only clean, but also had a positive effect on resistance to infectious diseases. Today, compounds with silicon serve as the basis for drugs against tuberculosis, atherosclerosis, and arthritis.
• In general, a non-metal is inactive, however, it is difficult to find it in its pure form. This is due to the fact that in air it is quickly passivated by a layer of dioxide and ceases to react. When heated, the chemical activity increases. As a result, humanity is much more familiar with the compounds of matter, and not with itself.

So, silicon forms alloys with almost all metals - silicides. All of them are distinguished by their refractoriness and hardness and are used in their respective areas: gas turbines, furnace heaters.

A non-metal is placed in the table of D. I. Mendeleev in group 6 along with carbon, germanium, which indicates a certain commonality with these substances. So, with carbon, it is “in common” with the ability to form compounds of the organic type. At the same time, silicon, like germanium, can exhibit the properties of a metal in some chemical reactions, which is used in synthesis.

Advantages and disadvantages

Like any other substance in terms of application in the national economy, silicon has certain useful or not very qualities. They are important for determining the area of ​​\u200b\u200buse.

• A significant advantage of the substance is its availability. In nature, however, it is not in a free form, but still, the technology for obtaining silicon is not so complicated, although it is energy-consuming.
• The second most important advantage is multiple compound formation with extraordinary benefits. These are silanes, and silicides, and dioxide, and, of course, various silicates. The ability of silicon and its compounds to form complex solid solutions is practically infinite, which makes it possible to endlessly obtain a variety of variations of glass, stone and ceramics.
• Semiconductor properties non-metal provides him with a place as a base material in electrical and radio engineering.
• Nonmetal is non-toxic, which allows application in any industry, and at the same time does not turn the technological process into a potentially dangerous one.

The disadvantages of the material include only relative brittleness with good hardness. Silicon is not used for load-bearing structures, but this combination makes it possible to properly process the surface of crystals, which is important for instrumentation.

Let's now talk about the main properties of silicon.

Properties and characteristics

Since crystalline silicon is most often used in industry, it is precisely its properties that are more important, and it is they that are given in the technical specifications. The physical properties of a substance are:

• melting point - 1417 C;
• boiling point - 2600 C;
• density is 2.33 g/cu. see, which indicates fragility;
• heat capacity, as well as thermal conductivity, are not constant even on the purest samples: 800 J / (kg K), or 0.191 cal / (g deg) and 84-126 W / (m K), or 0.20-0, 30 cal/(cm sec deg), respectively;
• transparent to long-wave infrared radiation, which is used in infrared optics;
• dielectric constant - 1.17;
• hardness on the Mohs scale - 7.

The electrical properties of a non-metal are highly dependent on impurities. In industry, this feature is used by modulating the desired type of semiconductor. At normal temperatures, silicon is brittle, but when heated above 800 C, plastic deformation is possible.

The properties of amorphous silicon are strikingly different: it is highly hygroscopic and reacts much more actively even at normal temperatures.

The structure and chemical composition, as well as the properties of silicon, are discussed in the video below:

Composition and structure

Silicon exists in two allotropic forms, equally stable at normal temperature.

• Crystal It has the appearance of a dark gray powder. The substance, although it has a diamond-like crystal lattice, is fragile - due to the too long bond between the atoms. Of interest are its semiconductor properties.
• At very high pressures, you can get hexagonal modification with a density of 2.55 g / cu. see However, this phase has not yet found practical significance.
• Amorphous- Brown powder. Unlike the crystalline form, it reacts much more actively. This is due not so much to the inertness of the first form, but to the fact that in air the substance is covered with a layer of dioxide.

In addition, it is necessary to take into account another type of classification associated with the size of the silicon crystal, which together form a substance. The crystal lattice, as is known, implies the ordering not only of atoms, but also of the structures that these atoms form - the so-called long-range order. The larger it is, the more homogeneous the substance will be in properties.

• monocrystalline– the sample is a single crystal. Its structure is as ordered as possible, the properties are homogeneous and well predictable. It is this material that is most in demand in electrical engineering. However, it also belongs to the most expensive type, since the process of obtaining it is complicated, and the growth rate is low.
• Multicrystalline– the sample consists of a number of large crystalline grains. The boundaries between them form additional defective levels, which reduces the performance of the sample as a semiconductor and leads to faster wear. The technology for growing a multicrystal is simpler, and therefore the material is cheaper.
• Polycrystalline- consists of a large number of grains arranged randomly relative to each other. This is the purest variety of industrial silicon, used in microelectronics and solar energy. Quite often it is used as a raw material for growing multi- and single crystals.
• Amorphous silicon also occupies a separate position in this classification. Here the order of the atoms is maintained only at the shortest distances. However, in electrical engineering, it is still used in the form of thin films.

Non-metal production

It is not so easy to obtain pure silicon, given the inertness of its compounds and the high melting point of most of them. In industry, carbon dioxide reduction is most often used. The reaction is carried out in arc furnaces at a temperature of 1800 C. Thus, a non-metal with a purity of 99.9% is obtained, which is not enough for its use.

The resulting material is chlorinated in order to obtain chlorides and hydrochlorides. Then the compounds are purified by all possible methods from impurities and reduced with hydrogen.

It is also possible to purify the substance by obtaining magnesium silicide. The silicide is subjected to the action of hydrochloric or acetic acid. Silane is obtained, and the latter is purified by various methods - sorption, rectification, and so on. Then the silane is decomposed into hydrogen and silicon at a temperature of 1000 C. In this case, a substance with an impurity fraction of 10 -8 -10 -6% is obtained.

Substance use

For industry, the electrophysical characteristics of non-metal are of the greatest interest. Its single-crystal form is an indirect-gap semiconductor. Its properties are determined by impurities, which makes it possible to obtain silicon crystals with desired properties. So, the addition of boron, indium makes it possible to grow a crystal with hole conductivity, and the introduction of phosphorus or arsenic - a crystal with electronic conductivity.

• Silicon literally serves as the basis of modern electrical engineering. Transistors, photocells, integrated circuits, diodes and so on are made from it. Moreover, the functionality of the device is almost always determined only by the near-surface layer of the crystal, which leads to very specific requirements for surface treatment.
• In metallurgy, technical silicon is used both as an alloy modifier - it gives greater strength, and as a component - in, for example, and as a deoxidizer - in the production of cast iron.
• Ultra-pure and refined metallurgical form the basis of solar energy.
• Non-metal dioxide occurs in nature in very different forms. Its crystalline varieties - opal, agate, carnelian, amethyst, rock crystal, have found their place in jewelry. Modifications that are not so attractive in appearance - flint, quartz, are used in metallurgy, and in construction, and in radio electrical engineering.
• The compound of a non-metal with carbon - carbide, is used in metallurgy, in instrument making, and in the chemical industry. It is a wide-gap semiconductor, characterized by high hardness - 7 on the Mohs scale, and strength, which allows it to be used as an abrasive material.
• Silicates - that is, salts of silicic acid. Unstable, easily decomposed under the influence of temperature. They are remarkable in that they form numerous and varied salts. But the latter are the basis for the production of glass, ceramics, faience, crystal, and. We can safely say that modern construction is based on a variety of silicates.
• Glass represents the most interesting case here. It is based on aluminosilicates, but insignificant impurities of other substances - usually oxides - give the material a lot of different properties, including color. -, earthenware, porcelain, in fact, has the same formula, although with a different ratio of components, and its diversity is also amazing.
• A non-metal has another ability: it forms carbon-type compounds, in the form of a long chain of silicon atoms. Such compounds are called organosilicon compounds. The scope of their application is no less known - these are silicones, sealants, lubricants, and so on.

Silicon is a very common element and is extremely important in many areas of the national economy. Moreover, not only the substance itself is actively used, but all its various and numerous compounds.

This video will talk about the properties and applications of silicon:

All names of chemical elements come from the Latin language. This is necessary, first of all, so that scientists from different countries can understand each other.

Chemical signs of the elements

Elements are usually denoted by chemical signs (symbols). At the suggestion of the Swedish chemist Berzelius (1813), chemical elements are denoted by the initial or initial and one of the subsequent letters of the Latin name of this element; The first letter is always uppercase, the second lowercase. For example, hydrogen (Hydrogenium) is denoted by the letter H, oxygen (Oxygenium) by the letter O, sulfur (Sulfur) by the letter S; mercury (Hydrargyrum) - with the letters Hg, aluminum (Aluminium) - Al, iron (Ferrum) - Fe, etc.

Rice. 1. Table of chemical elements with names in Latin and Russian.

Russian names of chemical elements are often Latin names with modified endings. But there are also many elements whose pronunciation differs from the Latin source. These are either native Russian words (for example, iron), or words that are a translation (for example, oxygen).

Chemical nomenclature

Chemical nomenclature - the correct name of chemicals. The Latin word nomenclatura translates as "a list of names, titles"

At an early stage in the development of chemistry, arbitrary, random names (trivial names) were given to substances. Volatile liquids were called alcohols, they included "hydrochloric alcohol" - an aqueous solution of hydrochloric acid, "silitry alcohol" - nitric acid, "ammonia alcohol" - an aqueous solution of ammonia. Oily liquids and solids were called oils, for example, concentrated sulfuric acid was called "vitriol oil", arsenic chloride - "arsenic oil".

Sometimes substances were named after their discoverer, for example, "Glauber's salt" Na 2 SO 4 * 10H 2 O, discovered by the German chemist I. R. Glauber in the 17th century.

Rice. 2. Portrait of I. R. Glauber.

The ancient names could indicate the taste of substances, color, smell, appearance, medical effect. One substance sometimes had several names.

By the end of the 18th century, no more than 150-200 compounds were known to chemists.

The first system of scientific names in chemistry was developed in 1787 by a commission of chemists headed by A. Lavoisier. Lavoisier's chemical nomenclature served as the basis for the creation of national chemical nomenclatures. In order for chemists from different countries to understand each other, the nomenclature must be unified. At present, the construction of chemical formulas and names of inorganic substances is subject to a system of nomenclature rules created by a commission of the International Union of Pure and Applied Chemistry (IUPAC). Each substance is represented by a formula, in accordance with which the systematic name of the compound is built.

Rice. 3. A. Lavoisier.

What have we learned?

All chemical elements have Latin roots. Latin names of chemical elements are generally accepted. In Russian, they are transferred using tracing or translation. however, some words have an original Russian meaning, such as copper or iron. Chemical nomenclature is subject to all chemical substances consisting of atoms and molecules. for the first time the system of scientific names was developed by A. Lavoisier.

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