Formula of a simple silicon substance. Silicon and its connections. Silicon in nature. Silicon use

The sequence number is 14, the charge of the core +14, protons in the core - 14, electrons - 14. The period of the period III - 14 electrons move along three energy levels. The number of the group IV - at the external energy level is 4 electrons. The radius of the atom is more than in carbon - the ability to return electrons increases. Metal and rehabilitation properties increase (in comparison with carbon). SI GE SN PB. general characteristics Silicon on position in periodic system. C.

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Silicon

"Silicon Lesson" - carbon dioxide about himself and humanity. Work in pairs, mutual test - no errors (5), two errors- (4), etc. 3% in the air - dizziness, noise in the ears, drowsiness. 20% - Everything for a person. On the manifestation of non-metallic and metal properties. Command estimate. What can be said about the size of the radii atoms from carbon to lead?

"Silicon and its compounds" - to consider natural silicon compounds. Give the overall characteristic element of silicon. Getting silicon. Silicon was first discovered in 1811 by Gay Lyssak and Terra. The structure and properties of atoms. Silicon oxide, in contrast to carbon oxide (IV), does not interact with water. Semiconductor. Tplant (Si) \u003d 1415? C, taplav (diamond) \u003d 3730? C.

"Silicon Isotopes" - obtaining polycrystalline silicon. The dependence of the position of the maximum of the band of combinational scattering from the atomic mass. Burner. Making a single crystal seed. Zono-purified silicon. Protective covering. The thermal conductivity of isotope-enriched silicon-28. Growing single crystals. The distribution of the concentration of isotopes by the length of the seed.

"Silicon compounds" - a variety of quartz. Jasper. Getting silicates. Natural silicates. Silicon oxide. Minerals based on SiO2. Chemical properties SiO2. Opening of silicon. Silicon and its connections. Silicon. Agate. The degree of oxidation. Electronic configuration. Silicates and hydrogen. Rhinestone. Finding in nature. Sylan.

"Carbon and silicon" - chemical properties. One of the most soft among solids. Silicate bricks. This mixture is called generator gas. Fig.1 Model of diamond lattice. The resulting gas consists of free nitrogen and carbon oxide (II). More than 99% of carbon in the atmosphere is contained in the form of carbon dioxide. Position in PSHE.

"Silicon" - until the end of the appearance of silicon is not enough 4 electrons. Silicon oxide (IV). The overall characteristic of silicon on the position in the periodic system. In silicon laboratories, restoring SiO2 silicon oxide. Physical properties. Silicates - salts of silicic acid. Silicate industry.

Total in the subject of 6 presentations

SILICON,Si (Silicium), chemical element IVA subgroup (C, Si, Ge, Sn and Pb) periodic system of elements, nonmetall. Silicon in free form was highlighted in 1811 J.G. Lyusadak and L.Terom when passing a silicon fluoride vapor over metallic potassium, but it was not described as an element. Swedish chemist Y. Bercelius in 1823 gave a description of silicon obtained by it when processing a potassium salt K 2 SIF 6 metal potassium at high temperatures, but only 1854 silicon was obtained in crystalline form A.Devil. Silicon is the second prevalence (after oxygen) an element in the earth's crust, where it is more than 25% (mass.). It is found in nature mainly in the form of sand, or silica, which is silicon dioxide, and in the form of silicates (field splits M (m \u003d Na, k, Ba), Al 4 kaolinite (OH) 8, mica). Silicon can be obtained by calcining crushed sand with aluminum or magnesium; In the latter case, it is separated from the resulting MGO dissolution of magnesium oxide in hydrochloric acid. Technical silicon is obtained in large quantities in electrical furnaces by recovering silica coal or coke. Semiconductor silicon is obtained by the reduction of SiCl 4 or SihCl 3 by hydrogen, followed by the decomposition of the sih 4 formed at 400-600 ° C. High-purity silicon is obtained by growing a single crystal from the melt of semiconductor silicon according to the Czokralsky method or the method of propellage melting of silicon rods. Elemental silicon is obtained mainly for semiconductor equipment, in other cases it is used as a doping additive in the production of steel and alloys of non-ferrous metals (for example, for obtaining FESI ferrosilica, which is formed by calcining the sand, coke and iron oxide in the electric furnace and is used as a deoxidizer. and a alloying supplement in the production of steels and as a reducing agent in the production of ferroalloys).

Application.

The greatest use of silicon finds in the production of alloys to give the strength of aluminum, copper and magnesium and for obtaining ferrosilicides, which are important in the production of steels and semiconductor equipment. Silicon crystals are used in solar panels and semiconductor devices - transistors and diodes. Silicon also serves as raw materials for the production of silicone compounds, or siloxanes obtained in the form of oils, lubricants, plastics and synthetic rubbers. Inorganic silicon compounds are used in ceramics and glass technologies, like insulating material and piezocrystals.

Properties of silicon
Atomic number	14
Atomic mass	28,086
Isotopes
Stable	28, 29, 30
Unstable	25, 26, 27, 31, 32, 33
Melting point, ° С	1410
Boiling temperature, ° С	2355
Density, g / cm 3	2,33
Hardness (MOO)	7,0
Contents in the earth's crust,% (mass.)	27,72
Oxidation degree	-4, +2, +4

Properties.

Silicon - darkness, brilliant crystalline substance, fragile and very solid, crystallizes in a diamond grille. This is a typical semiconductor (carries out electricity better than rubber type isolator, and worse than conductory - copper). At high temperature, silicon is very reactive and interacts with most elements, forming silicides, for example, MG 2 Si magnesium silicide, and other compounds, such as SiO 2 (silicon dioxide), SiF 4 (silicon tetrafluoride) and SiC (silicon carbide, carburund). Silicon dissolves in a hot alkali solution with hydrogen release: Si + NaOH ® Na 4 SiO 4 + 2H 2 -. 4 (silicon tetrachloride) is obtained from SiO 2 and CCl 4 at high temperatures; This is a colorless liquid, boiling at 58 ° C, easily hydrolyzed, forming chloride (hydrogen) HCl acid and H 4 SiO 4 oreccory (this property is used to create flue inscriptions: the highlighted HCl in the presence of ammonia forms a white ammonium chloride cloud NH 4 CL) . SIF 4 silicon tetrafluoride is formed under the action of fluoride (plating) acid on glass:

Na 2 SiO 3 + 6HF ® 2NAF + SIF 4 - + 3H 2 O

SiF 4 is hydrolyzed, forming an orthocremium and hexafluorocremia (H 2 SIF 6) acid. H 2 SIF 6 by power is close to sulfuric acid. Many fluorosilicates of metals are soluble in water (sodium salts, barium, potassium, rubidium, cesium are smallly soluble), so HF is used to transfer minerals into the solution when performing analyzes. Acid H 2 SIF 6 and her salt of poisonous.

One of the most sought-after elements in the technique and industry is silicon. It is obliged to this with its unusual properties. Today there are a lot of different compounds of this element that play an important role in the synthesis and creating technical products, dishes, glasses, equipment, construction and finishing materials, jewelry and in other industries.

General characteristic of silicon

If we consider the position of silicon in the periodic system, then we can say so:

1. Located in the IV group of the main subgroup.
2. Serial number 14.
3. Atomic weight 28.086.
4. Chemical SI symbol.
5. The name is silicon, or on Latin - Silicium.
6. Electronic configuration of the external layer 4E: 2e: 8e.

The crystal grate of silicon is similar to the diamond grille. In the nodes there are atoms, its type is cubic grazent. However, due to the longer communication length, the physical properties of silicon are very different from the properties of allotropic carbon modification.

Physical and chemical properties

A few more variations of silicon dioxide:

• quartz;
• river and;
• flint;
• fieldspar.

The use of silicon in such types is implemented in construction work, technician, electronics, chemical industries, metallurgy. All together listed oxides relate to a single substance - silica.

Silicon carbide and its application

Silicon and its compounds are the materials of the future and present. One of these materials is carborund or carbide of this element. Chemical formula SiC. It is found in nature in the form of Moissanite mineral.

In its pure form, the compound of carbon and silicon is beautiful transparent crystals resembling diamond structures. However, for technical purposes, the substances are painted in green and black colors.

The main characteristics of this substance, allowing it to be used in metallurgy, technique, chemical industry, are as follows:

• semiconductor wide;
• very high degree of strength (7 software;
• resistant to high temperatures;
• excellent electrically resistance and thermal conductivity.

All this allows the use of carbarund as an abrasive material in metallurgy and chemical synthesis. And on the basis of it, it is based on the wide range of a wide range of action, parts for glass cooker furnaces, nozzles, torches, jewelry (Moassanite is valued above the fianita).

Sylan and its meaning

Silicon's hydrogen compound is the name of silane and cannot be obtained by direct synthesis of starting materials. To obtain it, silicides of various metals are used, which are processed by acids. As a result, gaseous silane is released and a metal salt is formed.

Interestingly, the compound under consideration is never formed alone. Always as a result of the reaction, a mixture of mono-, di- and trisilane is obtained, in which silicon atoms are connected to the chain.

In its properties, these compounds are strong reducing agents. Itselves easily oxidized by oxygen, sometimes with an explosion. With the halogens of the reaction are always, with a large emission of energy.

The applications of silanes are as follows:

1. The reactions of organic synthesis, as a result of which important silicone compounds are formed - silicones, rubber, sealants, lubricants, emulsions and others.
2. Microelectronics (liquid crystal monitors, integral technical schemes, etc.).
3. Obtaining ultrapure polycamine.
4. Dentistry during prosthetics.

Thus, the meaning of silanes in modern world high.

Silicon Acid and Silicates

The hydroxide of the element under consideration is different silicic acids. Allocate:

• meta;
• ortho;
• polycreen and other acids.

All of them are united general properties - Extreme instability in free condition. They are easily decomposed under the action of temperature. Under normal conditions, there are not long, turning first into the sol, and then in the gel. After drying, such structures are called silica gels. They are used as adsorbents in filters.

Important, from the point of view of industry, are salts of silicon acids - silicates. They underlie the preparation of such substances as:

• glass;
• concrete;
• cement;
• zeolite;
• kaolin;
• porcelain;
• faience;
• crystal;
• ceramics.

Silicates of alkali metal - soluble, all others - no. Therefore, sodium and potassium silicate is called liquid glass. The usual stationery glue is a sodium silicic acid salt.

But the most interesting connections are still glass. What are the options for this substance or invented! Today get colored, optical, matte options. Glass utensils affects its splendor and diversity. When adding certain oxides of metals and non-metals, a variety of glass types can be obtained into the mixture. Sometimes even the same composition, but the different percentage of components leads to the difference in the properties of the substance. An example is the porcelain and faience, the formula of which SiO 2 * Al 2 O 3 * K 2 O.

Quartz glass is a form of a particularly clean product, the composition of which is described as silicon dioxide.

Discoveries in the field of silicon compounds

Over the past few years, studies have been proven that silicon and its compounds are the most important participants in the normal state of living organisms. With a disadvantage or excess of this element such diseases are associated as:

• tuberculosis;
• arthritis;
• cataract;
• leprosy;
• dysentery;
• rheumatism;
• hepatitis and others.

The anti-aging processes themselves are also associated with quantitative content of silicon. Numerous experiments on mammal animals proved that with a lack of an element, heart attacks, strokes, cancer, and the hepatitis virus is activated.

\u003e\u003e Chemistry: silicon and its connections

The second representative of the elements of the main subgroup of the IV group - silicon Si.

In nature silicon - The second prevalence after oxygen is a chemical element. The earth is more than a quarter consists of its compounds. The most common compound of silicon is its SiO2 dioxide, the other name is silica. In nature, it forms a quartz mineral (Fig. 46) and many varieties, such as rhinestone and its famous lilators - amethyst, as well as agate, opal, Yasma, Chalcedony, carnelian, who are known as diverse and semi-precious stones. Silicon dioxide is also ordinary and quartz sand.

From the varieties of minerals based on silicon dioxide - silicon, Chalcedone and other primitive people made tools of labor. It is the flint, this ineffective and not very durable stone, laid the beginning of the stone age - the century of flint tools of labor. There are two reasons for this: the prevalence and availability of silica, as well as its ability to form sharp cutting edges with the chole.

Fig. 46. \u200b\u200bNatural quartz crystal (left) and grown artificially (right)

The second type of natural silicon compounds is silicates. Among them are the most common aluminosilicates (it is clear that these silicates contain aluminum). Aluminosilicam includes granite, different kinds clay, mica. A silicate that does not contain aluminum is, for example, asbestos.

The most important compound of silicon - SiO2 oxide is necessary for the life of plants and animals. It gives strength to plants stalks and protective covering animals. Thanks to him, reeds, reeds and horses are tight, like bayonets, sharp leaves of the source cut, as knives, stroke on the beserved field, rolling like a needle, and stems of cereals are so strong that they do not allow Niva on the fields to lie down from rain and wind. Scales of fish, insect shells, butterflies wings, bird feathers and animal wool are durable, as they contain silica.

Silicon gives smoothness and strength of human bones.

Silicon is also included in the lowest living organisms - diatoms algae and radolarium, - the gentle lumps of living matter, which create their unsurpassed skeletons from silica.

Properties of silicon. If you use a microcalculator with a solar battery, then you probably have an idea of \u200b\u200bcrystalline silicon. This is a semiconductor. In contrast to metals with an increase in temperature, its electrical conductivity increases. On satellites, space ships and stations, solar batteries are installed, transforming solar energy into electric. They operate semiconductors crystals, and primarily silicon.

Silicon photocells can turn into electrical up to 10% absorbed solar energy.

Silicon burns in oxygen, forming a well-known silicon dioxide, or silicon oxide (1U):

Being non-metal, when heated, it connects with metals With the formation of silicides, for example:

Si + 2mg \u003d Mg2 Si

Silicides are easily decomposed with water or acids, with gaseous gas hydrogen connection Silicon - Sylan:

Mg2 Si + 2N2SO4 \u003d 2mgSO4 + Sih4

Unlike hydrocarbons, the air is silvan in air and burns and burns with the formation of silica and water dioxide:

Sih4 + 202 \u003d SiO2 + 2N2O

The increased reactivity of silane compared to methane CH4 is due to the fact that silicon is larger than the size of the atom than in carbon, so chemical ties -n weaker connections Sn.

Silicon interacts with concentrated aqueous solutions of alkalis, forming silicates and hydrogen :

Si + 2None + H20 \u003d Na2SiO3 + 2N2

Silicon is obtained by restoring it from magnesium dioxide or carbon.

Silicon oxide (IV), or silicon dioxide, or silica, as well as C02, is acidic oxide. However, in contrast to C02, it has no molecular, but a nuclear crystal grille. Therefore, SiO2 solid and refractory substance. It does not dissolve in water and acids, except as you know, the packing, but interacts at high temperatures with alkalis to form silicate salts - silicates.

Silicates can also be obtained by fusion of silicon dioxide with oxides Metals or with carbonates:

SiO2 + Sao \u003d SSIO3

SiO2 + CAS03 \u003d CASIO3 + C02

Solikates sodium and potassium are called soluble glass. Their aqueous solutions are well known silicate glue.

Of the solutions of silicates, the action of stronger acids - salt, sulfuric, acetic acid H2SIO3 is obtained from solid acids and even coal, sulfuric, acetic acid.

K2SIO3 + 2NSL \u003d 2xl + H2SIO3

Consequently, H2SiO3 is very weak acid. It is insoluble in water and falls out of the reaction mixture in the form of a shapeless sediment, sometimes filling compact all the volume of the solution, turning it into a semi-solid mass, like a jelly, jelly. With the drying of this mass, a high-art substance is formed - silica gel, widely used as an adsorbent - absorber of other substances.

Silicon use. You already know that silicon is used to obtain semiconductor materials, as well as acid-resistant alloys. When fusing quartz sand with coal at high temperatures, SIC silicon carbide is formed, which is only inferior to diamond. Therefore, it is used to drain the cutters of metal-cutting machines and grinding gemstones.

From the molten quartz, various quartz chemical dishes are made, which can withstand high temperatures and does not crack with sharp cooling.

Silicon compounds serve as the basis for the production of glass and cement.

Conventional window glass It has a composition that can be expressed by the formula

NA20 SAO 6SiO2.

It is obtained in special glass furnaces by fusion of soda, limestone and sand.

A distinctive feature of the glass is the ability to soften and in the molten state take any shape that is preserved when glass is frozen. This is based on the production of dishes and other glass products.

Glass is one of the most ancient inventions of humanity. Already 3-4 thousand years ago, glass production was developed in Egypt, Syria, Phenicia and Black Sea. High perfection in glassowels reached the master Ancient Rome. They knew how to get colored glasses and make mosaic glass from pieces of such glass.

Glass is a material not only artisans, but also artists. Works of art of glass are mandatory attributes of any major museum. And the colored stained glass windows churches, mosaic panels are bright examples. In one of the premises of the St. Petersburg branch Russian Academy Sci does is a mosaic portrait of Peter I, made by M. V. Lomonosov.

Additional quality glass give various additives. Thus, the introduction of lead oxide is obtained crystal glass, chromium oxide stains glass in green, cobalt oxide - in blue, etc.

The scope of glass is very extensive. This is a window, bottle, lamp, mirror glass; Optical glass - from glasses of glasses to glasses of cameras; Lens of countless optical devices - from microscopes to telescopes.

Another important material obtained on the basis of silicon compound is cement. It is obtained by sintering clay and limestone in special rotating furnaces. If cement powder is mixed with water, then cement dough is formed, or as construction workers, "solution", which gradually hardens. When adding sand or rubble to cement, a concrete is obtained as a filler. Concrete strength increases if iron frame is introduced into it, it turns out a reinforced concrete, from which wall panels, blocks of flooring, bridge farms, etc.

Silicate industry is engaged in the production of glass and cement. She also produces silicate ceramics - brick, porcelain, faience and products of them.

Opening of silicon . Although in deep ancient times, people widely used in their everyday a compound of silicon, silicon himself in elementary state was first obtained in 1825 by the Swedish chemist J. Ya. Bentselius. However, 12 years before him, silicon was received by J. Gay-Loussak and L. Tenar, but he was very polluted by impurities.

The Latin name Silicium originates from Lat. Silex - flint. The Russian name "silicon" comes from Greek. Cream - Rock, Rock.

1. Natural compounds of silicon: silica, quartz and its varieties, silicates, aluminosilicates, asbestos.

2. Biological significance of silicon.

3. Properties of silicon: semiconductor, interaction with oxygen, metals, alkalis.

5. Silicon oxide (IV). His structure and properties: interaction with alkalis, main oxides, carbonates and magnesium.

6. Silician acid and its salts. Soluble glass.

7. The use of silicon and its connections.

8. Glass.

9. Cement.

Specify the similarity and difference in carbon oxide (IV) and silicon oxide (IV) in structure and properties (interaction with water, alkalis, main oxides and magnesium). Write the reactions equations.

Why are carbon called the main element of wildlife, and silicon is the main element of inanimate nature?

In the interaction of an excess solution of sodium hydroxide with 16 g of silicon, 22.4 liters of hydrogen were obtained. What is the mass fraction of silicon in the sample? How many grams of silicon oxide contained in it? How many grams of 60% alkali solutions needed to reaction?

Write the reaction equations with which the following transformations can be carried out:

a) SiO2 -\u003e si -\u003e sa2si -\u003e sih4 -\u003e sio2 -\u003e si

b) Si -\u003e SiO2 -\u003e NA2SIO3 -\u003e H2SIO3 -\u003e SiO2 -\u003e Si

Consider the recovery oxidation processes.

The famous scholar in the field of mineralogy A. E. Fersman wrote: "Show a wide variety of items: a transparent ball, sparkling in the sun Clean Water Clear Water, beautiful, Motley drawing agate, bright game Multicolor opal, clean sand on the seashore, thin, like silk , melted quartz thread or heatpowder dishes made of it, beautifully fears of rock crystal, mysterious drawing of a fantastic jasper, a petrified tree, turned into a stone, roughly treated arrow tip of an ancient person ... All this is the same connection ... "What ? Finish the quote.

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