Tin how to read. The structure of the tin atom. The most important natural compounds

1s 2 2s 2 2p 6 3s 2 3p 6 3d 10 4s 2 4p 5 .

Valence electrons are in bold. Belongs to the family of p-elements. Since the largest principal quantum number is 4, and the number of electrons in the outer energy level is 7, bromine is located in the 4th period, Group VIIA of the Periodic Table. The energy diagram for valence electrons is:

Germanium.

1s 2 2s 2 2p 6 3s 2 3p 6 3d 10 4s 2 4p 2 .

Valence electrons are in bold. Belongs to the p-element family. Since the largest principal quantum number is 4 and the number of electrons in the outer energy level is 4, germanium is located in the 4th period, the IVA group of the Periodic Table. The energy diagram for valence electrons is:

Cobalt.

1s 2 2s 2 2p 6 3s 2 3p 6 3d 7 4s 2 .

Valence electrons are in bold. Belongs to the family of d-elements. Cobalt is located in the 4th period, group VIIB of the Periodic Table. The energy diagram for valence electrons is:

Copper.

1s 2 2s 2 2p 6 3s 2 3p 6 3d 10 4s 1 .

Valence electrons are in bold. Belongs to the family of d-elements. Since the largest principal quantum number is 4, and the number of electrons in the outer energy level is 1, copper is located in the 4th period, Group I of the Periodic Table. The energy diagram for valence electrons has the form.

Light non-ferrous metal, simple inorganic substance. In the periodic table it is designated Sn, stannum (stannum). Translated from Latin, it means "strong, resistant." Initially, this word was called an alloy of lead and silver, and only much later pure tin began to be called that. The word "tin" has Slavic roots and means "white".

Metal refers to scattered elements, and not the most common on earth. In nature, it occurs in the form of various minerals. The most important for industrial mining: cassiterite - tin stone, and stannin - tin pyrite. Tin is mined from ores, usually containing no more than 0.1 percent of this substance.

Tin properties

Lightweight soft ductile silver-white metal. It has three structural modifications, passes from the state of α-tin (grey tin) to β-tin (white tin) at a temperature of +13.2 °C, and to the state of γ-tin at t +161 °C. Modifications are very different in their properties. α-tin is a gray powder, which is classified as a semiconductor, β-tin (“ordinary tin” at room temperature) is a silver malleable metal, γ-tin is a white brittle metal.

In chemical reactions, tin exhibits polymorphism, that is, acidic and basic properties. The reagent is quite inert in air and in water, as it is quickly covered with a strong oxide film that protects it from corrosion.

Tin easily reacts with non-metals, with difficulty - with concentrated sulfuric and hydrochloric acid; it does not interact with these acids in a dilute state. It reacts with concentrated and dilute nitric acid, but in different ways. In one case, tin acid is obtained, in the other, tin nitrate. It reacts with alkalis only when heated. It forms two oxides with oxygen, with oxidation states 2 and 4. It is the basis of a whole class of organotin compounds.

Impact on the human body

Tin is considered safe for humans, it is in our body and every day we get it in minimal quantities with food. Its role in the functioning of the body has not yet been studied.

Tin vapor and its aerosol particles are dangerous, since prolonged and regular inhalation can cause lung diseases; organic compounds of tin are also poisonous, so it is necessary to work with it and its compounds in protective equipment.

Such a tin compound as hydrogen tin, SnH 4, can cause severe poisoning when eating very old canned food, in which organic acids have reacted with a layer of tin on the walls of the can (the tin from which cans are made is a thin sheet of iron, coated on both sides with tin). Hydrogen tin poisoning can even be fatal. Its symptoms include convulsions and a feeling of loss of balance.

When the air temperature drops below 0 °C, white tin transforms into gray tin. At the same time, the volume of the substance increases by almost a quarter, the tin product cracks and turns into a gray powder. This phenomenon became known as the "tin plague".

Some historians believe that the "tin plague" was one of the reasons for the defeat of Napoleon's army in Russia, as it turned the buttons on the clothes of French soldiers and belt buckles into powder, and thus had a demoralizing effect on the army.

And here is a real historical fact: the expedition of the English polar explorer Robert Scott to the South Pole ended tragically, including because all their fuel spilled out of the tanks sealed with tin, they lost their snowmobiles, and they didn’t have enough strength to walk.

Application

Most of the smelted tin is used in metallurgy for production of various alloys. These alloys are used in the manufacture of bearings, foil for packaging, food grade tin, bronze, solders, wires, and typographic fonts.
- Tin in the form of foil (staniol) is in demand in the production of capacitors, dishes, art products, organ pipes.
- Used for alloying structural titanium alloys; for applying anti-corrosion coatings on products made of iron and other metals (tinning).
- Alloy with zirconium has high refractoriness and corrosion resistance.
- Tin (II) oxide - used as an abrasive in the processing of optical glasses.
- Included in the composition of materials used for the manufacture of batteries.
- By production of paints "under gold", dyes for wool.
- Artificial radioisotopes of tin are used as a source of γ-radiation in spectroscopic research methods in biology, chemistry, and materials science.
- Tin chloride (tin salt) is used in analytical chemistry, in the textile industry for dyeing, in the chemical industry for organic synthesis and polymer production, in oil refining - for decolorizing oils, in the glass industry - for glass processing.
- Tin boron is used for the manufacture of tin, bronze, and other alloys needed by the industry; for tinning; lamination.

TIN (lat. Stannum), Sn, chemical element with atomic number 50, atomic mass 118.710. There are various conjectures about the origin of the words "stannum" and "tin". The Latin "stannum", which is sometimes derived from the Saxon "hundred" - strong, hard, originally meant an alloy of silver and lead. "Tin" in a number of Slavic languages ​​was called lead. Perhaps the Russian name is associated with the words "ol", "tin" - beer, mash, honey: tin vessels were used to store them. In English literature, the word tin is used for the name of tin. The chemical symbol for tin is Sn, which reads "stannum".

Natural tin consists of nine stable nuclides with mass numbers 112 (in a mixture of 0.96% by mass), 114 (0.66%), 115 (0.35%), 116 (14.30%), 117 (7, 61%), 118 (24.03%), 119 (8.58%), 120 (32.85%), 122 (4.72%), and one weakly radioactive tin-124 (5.94%). 124Sn is a b-emitter, its half-life is very long and is T1/2 = 1016-1017 years. Tin is located in the fifth period in the IVA group of the periodic table of elements of D. I. Mendeleev. The configuration of the outer electron layer is 5s25p2. In its compounds, tin exhibits oxidation states +2 and +4 (valencies II and IV, respectively).

The metallic radius of the neutral tin atom is 0.158 nm, the radii of the Sn2+ ion are 0.118 nm and the radii of the Sn4+ ion are 0.069 nm (coordination number 6). The sequential ionization energies of a neutral tin atom are 7.344 eV, 14.632, 30.502, 40.73, and 721.3 eV. According to the Pauling scale, the electronegativity of tin is 1.96, that is, tin is on the conditional border between metals and non-metals.

Information about chemistry

Radiochemistry

Radiochemistry - studies the chemistry of radioactive substances, the laws of their physical and chemical behavior, the chemistry of nuclear transformations and the accompanying physical and chemical processes. Radiochemistry has the following features: work with...

Stark, Johannes

The German physicist Johannes Stark was born in Schickenhof (Bavaria) into a landowner's family. He studied at the secondary schools of Bayreuth and Regensburg, and in 1894 he entered the University of Munich, where in 1897 he defended his doctoral dissertation...

Th - Thorium

THORIUM (lat. Thorium), Th, a chemical element of group III of the periodic system, atomic number 90, atomic mass 232.0381, refers to actinides. Properties: radioactive, the most stable isotope is 232Th (half-life 1.389&m ...

Tin(lat. Stannum), Sn, a chemical element of group IV of the periodic system of Mendeleev; atomic number 50, atomic mass 118.69; white shiny metal, heavy, soft and ductile. The element consists of 10 isotopes with mass numbers 112, 114-120, 122, 124; the latter is weakly radioactive; the isotope 120 Sn is the most common (about 33%).

History reference. O.'s alloys with copper - bronze were already known in the 4th millennium BC. e., and pure metal in the 2nd millennium BC. e. In the ancient world, jewelry, dishes, and utensils were made from jewelry. The origin of the names "stannum" and "tin" is not exactly established.

distribution in nature. O. - a characteristic element of the upper part of the earth's crust, its content in the lithosphere is 2.5 10 = 4% by weight, in acidic igneous rocks 3 10 = 4%, and in deeper basic 1.5 10 = 4%; even less O. in the mantle. O. concentration is associated both with magmatic processes (tin-bearing granites and pegmatites enriched with O. are known) and with hydrothermal processes. Of the 24 known O. minerals, 23 were formed at high temperatures and pressures. The main industrial value is cassiterite SnO 2, lesser - stannin Cu 2 FeSnS 4 (see. Tin ores). O. migrates weakly in the biosphere; sea ​​water it is only 3 10 = 7%; aquatic plants with a high content of oxygen are known. However, the general trend in the geochemistry of oxygen in the biosphere is dispersion.

Physical and Chemical properties. O. has two polymorphic modifications. The crystal lattice of ordinary b-Sn (white O.) is tetragonal with periods a = 5,813 , With=3.176; density 7.29 G/cm 3 . At temperatures below 13.2 °C stable a-Sn (grey O.) cubic structure such as diamond; density 5.85 G/cm 3 . The b a transition is accompanied by the transformation of the metal into powder (see Fig. tin plague), t pl 231.9 °C, t kip 2270 °C. Temperature coefficient linear expansion 23 10 =6 (0-100 °C); specific heat (0°C) 0.225 kJ/(kg K), i.e. 0.0536 feces/(G°C); thermal conductivity (0 °C) 65.8 Tue/(m K), i.e. 0.157 feces/(cm·- sec°C); electrical resistivity (20 °C) 0.115 10 =6 ohm· m, i.e. 11.5 10 =6 ohm· cm.Tensile strength 16.6 Mn/m 2 (1,7 kgf/mm 2)" , elongation 80-90%; Brinell hardness 38.3-41.2 Mn/m 2 (3,9-4,2 kgf/mm 2). When the O. bars are bent, a characteristic crunch is heard from the mutual friction of the crystallites.

According to the configuration of the outer electrons of the atom 5 s 2 5p 2 O. has two oxidation states: +2 and +4; the latter is more stable; Sn(P) compounds are strong reducing agents. Dry and humid air at temperatures up to 100 °C practically does not oxidize O.: it is protected by a thin, strong and dense film of SnO 2 . In relation to cold and boiling water, O. is stable. The standard electrode potential of O. in an acidic environment is - 0.136 v. O. slowly displaces hydrogen from dilute HCl and H 2 SO 4 in the cold, forming SnCl 2 chloride and SnSO 4 sulfate, respectively. O. dissolves in hot concentrated H 2 SO 4 when heated, forming Sn (SO 4) 2 and SO 2. Cold (O ° C) dilute nitric acid acts on O. according to the reaction:

4Sn + 10HNO 3 \u003d 4Sn (NO 3) 2 + NH 4 NO 3 + 3H 2 O.

When heated with concentrated HNO 3 (density 1.2-1.42 G/cm 3) O. is oxidized with the formation of a precipitate of metatinic acid H 2 SnO 3, the degree of hydration of which is variable:

3Sn+ 4HNO 3 + n H 2 O \u003d 3H 2 SnO 3 n H2O + 4NO.

When oxygen is heated in concentrated alkali solutions, hydrogen is released and hexahydrostannate is formed:

Sn + 2KOH + 4H 2 O \u003d K 2 + 2H 2.

Air oxygen passivates oxygen, leaving a film of SnO 2 on its surface. Chemically, SnO 2 dioxide is very stable, and SnO oxide is rapidly oxidized, it is obtained indirectly. SnO 2 exhibits predominantly acidic properties, SnO - basic.

O. does not combine directly with hydrogen; hydride SnH 4 is formed by the interaction of Mg 2 Sn and hydrochloric acid:

Mg 2 Sn + 4HCl \u003d 2MgCl 2 + SnH 4.

It is a colorless poisonous gas t kip -52 °C; it is very fragile, at room temperature it decomposes into Sn and H 2 within a few days, and above 150 ° C - instantly. It is also formed under the action of hydrogen at the time of release to O. salts, for example:

SnCl 2 + 4HCl + 3Mg \u003d 3MgCl 2 + SnH 4.

With halogens, O. gives compounds of the composition SnX 2 and SnX 4 . The former are salt-like and in solutions give Sn 2+ ions, the latter (except for SnF 4) are hydrolyzed by water, but are soluble in non-polar organic liquids. O.'s interaction with dry chlorine (Sn + 2Cl 2 = SnCl 4) gives SnCl 4 tetrachloride; it is a colorless liquid, well dissolving sulfur, phosphorus, iodine. Previously, O. was removed from failed tinned products using the above reaction. Now the method is not widely used due to the toxicity of chlorine and high losses of oxygen.

Tetrahalides SnX 4 form complex compounds with H 2 O, NH 3 , nitrogen oxides, PCl 5 , alcohols, ethers and many organic compounds. With hydrohalic acids, O. halides give complex acids that are stable in solutions, such as H 2 SnCl 4 and H 2 SnCl 6 . When diluted with water or neutralized, solutions of simple or complex chlorides are hydrolyzed, giving white precipitates of Sn (OH) 2 or H 2 SnO 3 · n H 2 O. With sulfur O. gives sulfides insoluble in water and dilute acids: brown SnS and golden yellow SnS 2.

Receipt and application. The industrial production of O. is advisable if its content in placers is 0.01%, in ores 0.1%; usually tenths and units of percent. O. in ores are often accompanied by W, Zr, Cs, Rb, rare earth elements, Ta, Nb, and other valuable metals. Primary raw materials are enriched: placers - mainly by gravity, ores - also by flotation or flotation.

Concentrates containing 50–70% oxygen are fired to remove sulfur and purified from iron by the action of HCl. If impurities of wolframite (Fe, Mn) WO 4 and scheelite CaWO 4 are present, the concentrate is treated with HCl; the resulting WO 3 ·H 2 O is taken up with NH 4 OH. By smelting concentrates with coal in electric or flame furnaces, rough O. (94–98% Sn) is obtained, containing impurities of Cu, Pb, Fe, As, Sb, and Bi. When released from furnaces, draft iron is filtered at a temperature of 500–600 °C through coke or centrifuged, thereby separating the bulk of the iron. The rest of Fe and Cu is removed by mixing elemental sulfur into the liquid metal; impurities float up in the form of solid sulfides, which are removed from the surface of the oxygen. From arsenic and antimony, oxygen is refined in a similar way - by mixing in aluminum, from lead - with the help of SnCl 2 . Sometimes Bi and Pb are evaporated in vacuum. Electrolytic refining and zone recrystallization are relatively rarely used to obtain highly pure O.

About 50% of all produced O. is secondary metal; it is obtained from waste tinplate, scrap and various alloys. Up to 40% of gold is used for tinning tinplate, and the rest is spent on the production of solders, bearings, and printing alloys. Tin alloys). Dioxide SnO 2 is used for the manufacture of heat-resistant enamels and glazes. Salt - sodium stannite Na 2 SnO 3 3H 2 O is used in stain dyeing of fabrics. Crystalline SnS 2 ("gold leaf") is part of paints that imitate gilding. Niobium stannide Nb 3 Sn is one of the most used superconducting materials.

N. N. Sevryukov.

O.'s toxicity and the majority of its inorganic connections is small. The acute poisonings caused by elemental O. widely used in the industry practically do not meet. Separate cases of poisoning described in the literature, apparently, are caused by the release of AsH 3 when water accidentally gets into the waste of cleaning O. from arsenic. The workers of tin-smelting plants, with prolonged exposure to dust, oxides of O. (the so-called black O., SnO) may develop pneumoconiosis, workers involved in the manufacture of tin foil sometimes have cases of chronic eczema. Tetrachloride O. (SnCl 4 5H 2 O) at its concentration in the air over 90 mg/m 3 irritant to the upper respiratory tract, causing coughing; getting on the skin, O. chloride causes its ulceration. A strong convulsive poison is hydrogen stannous (stannomethane, SnH 4), but the probability of its formation under industrial conditions is negligible. Severe poisoning when eating long-made canned food can be associated with the formation of SnH 4 in cans (due to the action of organic acids on the cans of the contents). Acute poisoning with tinous hydrogen is characterized by convulsions, imbalance; death is possible.

O. organic compounds, especially di- and trialkyl ones, have a pronounced effect on the central nervous system. Signs of poisoning with trialkyl compounds: headache, vomiting, dizziness, convulsions, paresis, paralysis, visual disturbances. Quite often develop a coma (see. Coma), cardiac and respiratory disorders with a fatal outcome. Toxicity of O.'s dialkyl compounds is somewhat lower; in the clinical picture of poisoning, symptoms of damage to the liver and biliary tract predominate. Prevention: observance of the rules of occupational health.

O. as an artistic material. Excellent casting properties, malleability, pliability with a cutter, and a noble silvery-white color led to the use of O. in arts and crafts. In ancient Egypt, gold was used to make jewelry soldered onto other metals. From the end of the 13th century In Western European countries, vessels and church utensils made of O. appeared, similar to silver, but softer in outline, with a deep and rounded engraving stroke (inscriptions, ornaments). In the 16th century F. Briot (France) and K. Enderlein (Germany) began to cast ceremonial bowls, dishes, and goblets from O. with relief images (coats of arms, mythological, genre scenes). A. Sh. Boole introduced O. into marquetry when decorating furniture. In Russia, objects made of silverware (mirror frames, utensils) became widespread in the 17th century; in the 18th century in the north of Russia, the production of copper trays, teapots, snuff boxes, trimmed with tin overlays with enamels, reached its peak. By the beginning of the 19th century. O. vessels gave way to faience, and the use of O. as an artistic material became rare. The aesthetic merits of contemporary decorative items made of O. are in the clear identification of the object's structure and the mirror-like surface purity, which is achieved by casting without further processing.

Lit.: Sevryukov N. N., Tin, in the book: Brief Chemical Encyclopedia, vol. 3, M., 1963, p. 738-39; Metallurgy of tin, M., 1964; Nekrasov B.V., Fundamentals of General Chemistry, 3rd ed., Vol. 1, M., 1973, p. 620-43; Ripan R., Chetyanu I., Inorganic chemistry, part 1 - Chemistry of metals, trans. from rum., M., 1971, p. 395-426; Occupational diseases, 3rd ed., M., 1973; Harmful substances in industry, part 2, 6th ed., M, 1971; Tardy, Les étspan>francais, pt. 1-4, P., 1957-64; Mory L., Schönes Zinn, Münch., 1961; Haedeke H., Zinn, Braunschweig, 1963.

Each chemical element of the periodic system and the simple and complex substances formed by it are unique. They have unique properties, and many make an undeniably significant contribution to human life and existence in general. The chemical element tin is no exception.

Acquaintance of people with this metal goes back to ancient times. This chemical element played a decisive role in the development of human civilization; to this day, the properties of tin are widely used.

Tin in history

The first mention of this metal, which, as people believed before, even had some magical properties, can be found in biblical texts. Tin played a decisive role in improving life during the Bronze Age. At that time, the most durable metal alloy that a person possessed was bronze, which can be obtained by adding the chemical element tin to copper. For several centuries, everything was made from this material, from tools to jewelry.

After the discovery of the properties of iron, the tin alloy did not cease to be used, of course, it is not used on the same scale, but bronze, as well as many of its other alloys, are actively involved in industry, technology and medicine today, along with salts of this metal, such as chloride. tin, which is obtained by the interaction of tin with chlorine, this liquid boils at 112 degrees Celsius, dissolves well in water, forms crystalline hydrates and smokes in air.

The position of the element in the periodic table

The chemical element tin (the Latin name stannum is “stannum”, written with the symbol Sn) Dmitry Ivanovich Mendeleev rightfully placed at number fifty, in the fifth period. It has a number of isotopes, the most common is the 120 isotope. This metal is also found in main subgroup from the sixth group, together with carbon, silicon, germanium and flerovium. Its location predicts amphoteric properties, and tin has equally acidic and basic characteristics, which will be described in more detail below.

The periodic table also shows the atomic mass of tin, which is 118.69. The electronic configuration 5s 2 5p 2, which in the composition of complex substances allows the metal to exhibit oxidation states +2 and +4, giving up two electrons only from the p-sublevel or four from s- and p-, completely emptying the entire external level.

Electronic characteristic of the element

In accordance with the atomic number, the circumnuclear space of the tin atom contains as many as fifty electrons, they are located on five levels, which, in turn, are split into a number of sublevels. The first two have only s- and p-sublevels, and starting from the third there is a triple splitting into s-, p-, d-.

Let us consider the external one, since it is its structure and filling with electrons that determine the chemical activity of the atom. In the unexcited state, the element exhibits a valence equal to two; upon excitation, one electron passes from the s-sublevel to a vacancy in the p-sublevel (it can contain a maximum of three unpaired electrons). In this case, tin exhibits valency and oxidation state - 4, since there are no paired electrons, which means that nothing holds them at the sublevels in the process of chemical interaction.

Simple substance metal and its properties

Tin is a silver-colored metal, belongs to the group of fusible. The metal is soft and relatively easy to deform. A number of features are inherent in such a metal as tin. A temperature below 13.2 is the boundary of the transition of the metal modification of tin to powder, which is accompanied by a change in color from silver-white to gray and a decrease in the density of the substance. Tin melts at 231.9 degrees and boils at 2270 degrees Celsius. The crystalline tetragonal structure of white tin explains the characteristic crunching of the metal when it is bent and heated at the point of inflection by rubbing the crystals of the substance against each other. Gray tin has a cubic syngony.

The chemical properties of tin have a dual essence, it enters into both acidic and basic reactions, showing amphotericity. The metal interacts with alkalis, as well as acids, such as sulfuric and nitric, and is active when reacting with halogens.

Tin alloys

Why are their alloys with a certain percentage of constituent components used more often instead of pure metals? The fact is that the alloy has properties that an individual metal does not have, or these properties are much stronger (for example, electrical conductivity, corrosion resistance, passivation or activation of the physical and chemical characteristics of metals, if necessary, etc.). Tin (the photo shows a sample of pure metal) is part of many alloys. It can be used as an additive or base substance.

To date, a large number of alloys of such a metal as tin are known (the price for them varies widely), we will consider the most popular and used ones (the use of certain alloys will be discussed in the appropriate section). In general, stannum alloys have the following characteristics: high ductility, low small hardness and strength.

Some examples of alloys

The most important natural compounds

Tin forms a number of natural compounds - ores. The metal forms 24 mineral compounds, the most important for industry is tin oxide - cassiterite, as well as frame - Cu 2 FeSnS 4. Tin is scattered in the earth's crust, and the compounds formed by it are of magnetic origin. Salts of polyolic acids and tin silicates are also used in industry.

Tin and the human body

The chemical element tin is a trace element in terms of its quantitative content in the human body. Its main accumulation is in the bone tissue, where the normal content of the metal contributes to its timely development and the overall functioning of the musculoskeletal system. In addition to bones, tin is concentrated in the gastrointestinal tract, lungs, kidneys, and heart.

It is important to note that excessive accumulation of this metal can lead to general poisoning of the body, and longer exposure can even lead to adverse gene mutations. Recently, this problem is quite relevant, since the ecological state of the environment leaves much to be desired. There is a high probability of tin intoxication among residents of megacities and areas nearby near industrial zones. Most often, poisoning occurs through the accumulation of tin salts in the lungs, for example, such as tin chloride and others. At the same time, a micronutrient deficiency can cause growth retardation, hearing loss and hair loss.

Application

The metal is commercially available from many smelters and companies. It is produced in the form of ingots, rods, wires, cylinders, anodes made from a pure simple substance such as tin. The price ranges from 900 to 3000 rubles per kg.

Tin in pure form rarely used. Its alloys and compounds are mainly used - salts. Soldering tin is used in the case of fastening parts that are not exposed to high temperatures and strong mechanical loads, made of copper alloys, steel, copper, but is not recommended for those made of aluminum or its alloys. The properties and characteristics of tin alloys are described in the corresponding section.

Solders are used for soldering microcircuits, in this situation alloys based on a metal such as tin are also ideal. The photo depicts the process of applying a tin-lead alloy. With it, you can perform quite delicate work.

Due to the high resistance of tin to corrosion, it is used for the manufacture of tinned iron (tinplate) - food cans. In medicine, in particular in dentistry, tin is used to fill teeth. House pipelines are covered with tin, bearings are made of its alloys. The contribution of this substance to electrical engineering is also invaluable.

Aqueous solutions of tin salts such as fluoroborates, sulfates, and chlorides are used as electrolytes. Tin oxide is a glaze for ceramics. By introducing various tin derivatives into plastic and synthetic materials, it seems possible to reduce their flammability and the emission of harmful fumes.