Position of metals in the periodic table

If we draw a diagonal from boron to astatine in the table of D.I. Elements located near the diagonal have dual properties: in some of their compounds they behave like metals; in some - as non-metals.

The structure of metal atoms

In periods and main subgroups, there are regularities in the change in metallic properties.

Many metal atoms have 1, 2, or 3 valence electrons, for example:

Na (+ 11): 1S2 2S22p6 3S1

Ca (+ 20): 1S2 2S22p6 3S23p63d0 4S2

Alkali metals (group 1, main subgroup): ... nS1.

Alkaline earth (group 2, main subgroup): ... nS2.

The properties of metal atoms are periodically dependent on their location in DI Mendeleev's table.

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a - copper; b - magnesium; c - α-modification of iron

Metal atoms tend to donate their outer electrons. In a piece of metal, ingot or metal product, the metal atoms give up external electrons and send them to this piece, ingot or product, thus turning into ions. The "torn off" electrons move from one ion to another, temporarily reunite with them into atoms, torn off again, and this process occurs continuously. Metals have a crystal lattice, in the nodes of which there are atoms or ions (+); between them are free electrons (electron gas). The communication scheme in metal can be displayed as follows:

М0 ↔ nē + Мn +,

atom - ion

where n Is the number of external electrons participating in the bond (y Na - 1 ē, at Ca - 2 ē, at Al - 3 ē).

This type of bond is observed in metals - simple substances - metals and in alloys.

A metallic bond is a bond between positively charged metal ions and free electrons in the crystal lattice of metals.

The metallic bond has some similarity with the covalent bond, but also some difference, since the metal bond is based on the socialization of electrons (similarity), all atoms take part in the socialization of these electrons (difference). That is why crystals with a metallic bond are ductile, electrically conductive and have a metallic luster. However, in the vapor state, metal atoms are linked by a covalent bond, metal pairs are composed of individual molecules (monoatomic and diatomic).

General characteristics of metals

The ability of atoms to donate electrons (oxidize)	← Increasing
Interaction with atmospheric oxygen	Oxidizes quickly at ambient temperatures	Oxidize slowly at normal temperature or when heated	Do not oxidize
Interaction with water	At normal temperatures, H2 is released and hydroxide is formed	When heated, H2 is released	H2 is not displaced from water
5interaction with acids	Displace H2 from dilute acids	Does not displace H2 from dilute acids
React with conc. and decomp. HNO3 and with conc. H2SO4 when heated	Do not react with acids
Being in nature	Only in connections	In connections and in free form	Mostly loose
Methods of obtaining	Electrolysis of melts	Reduction with coal, carbon monoxide (2), alumothermy, or electrolysis of aqueous solutions of salts
The ability of ions to attach electrons (recover)	Li K Ca Na Mg Al Mn Zn Cr Fe Ni Sn Pb (H) Cu Hg Ag Pt Au
Increasing →

Electrochemical series of metal voltages. Physical and chemical properties of metals

General physical properties of metals

The general physical properties of metals are determined by the metallic bond and the metallic crystal lattice.

Malleability, ductility

Mechanical action on a metal crystal causes a displacement of the layers of atoms. Since the electrons in the metal move throughout the crystal, no breaking of bonds occurs. Plasticity decreases in a row Au, Ag, Cu, Sn, Pb, Zn, Fe... Gold, for example, can be rolled into sheets no more than 0.001 mm thick, which are used for gilding various items. Aluminum foil appeared relatively recently and earlier tea, chocolate was forged into tin foil, which was called stanyol. However, Mn and Bi do not have ductility: these are brittle metals.

Metallic luster

Metallic luster, which in the powder is lost by all metals, except Al and Mg... The brightest metals are Hg(the famous "Venetian mirrors" were made from it in the Middle Ages), Ag(now modern mirrors are made from it with the help of the reaction of the "silver mirror"). By color (conventionally), ferrous and non-ferrous metals are distinguished. Among the latter, we will single out precious ones - Au, Ag, Pt. Gold is the metal of jewelers. It was on its basis that wonderful Faberge Easter eggs were made.

Ringing

Metals ring, and this property is used to make bells (remember the Tsar Bell in the Moscow Kremlin). The most sonorous metals are Au, Ag, Ci. Copper rings with a thick, humming ring - a crimson ring. This is a figurative expression not in honor of the raspberry berry, but in honor of the Dutch city of Malina, where the first church bells were melted. Later in Russia, Russian craftsmen began to cast bells of even better quality, and residents of cities and towns donated gold and silver jewelry so that the bell cast for churches would sound better. In some Russian pawnshops, the authenticity of gold rings accepted for commission was determined by the ringing of a gold wedding ring suspended from a woman's hair (a very long and clear high-pitched sound is heard).

Under normal conditions, all metals except mercury Hg are solids. The hardest metal is chromium Cr, which scratches glass. The softest are alkali metals, they are cut with a knife. Alkali metals are stored with great precautions - Na - in kerosene, and Li - in petroleum jelly because of its lightness, kerosene - in a glass jar, a jar - in asbestos chips, asbestos - in a tin can.

Electrical conductivity

The good electrical conductivity of metals is explained by the presence of free electrons in them, which, under the influence of even a small potential difference, acquire a directional movement from the negative to the positive pole. As the temperature rises, the vibrations of atoms (ions) intensify, which makes it difficult for the directional movement of electrons and thereby leads to a decrease in electrical conductivity. At low temperatures, the vibrational motion, on the contrary, greatly decreases and the electrical conductivity increases sharply. Metals exhibit superconductivity near absolute zero. Ag, Cu, Au, Al, Fe have the highest electrical conductivity; worst conductors - Hg, Pb, W.

Thermal conductivity

Under normal conditions, the thermal conductivity of metals changes in basically the same sequence as their electrical conductivity. Thermal conductivity is due to the high mobility of free electrons and the vibrational motion of atoms, due to which there is a rapid equalization of temperature in the mass of the metal. The highest thermal conductivity is in silver and copper, the lowest is in bismuth and mercury.

Density

The density of metals is different. It is the less, the less the atomic mass of the metal element and the larger the radius of its atom. The lightest metal is lithium (density 0.53 g / cm3), the heaviest is osmium (density 22.6 g / cm3). Metals with a density of less than 5 g / cm3 are called light, the rest are called heavy.

The melting and boiling points of metals are varied. The most low-melting metal - mercury (boiling point = -38.9 ° С), cesium and gallium - melt at 29 and 29.8 ° С, respectively. Tungsten is the most refractory metal (bp = 3390 ° C).

The concept of allotropy of metals on the example of tin

Some metals have allotropic modifications.

For example, tin is distinguished into:

· Α-tin, or gray tin ("tin plague" - the transformation of ordinary β-tin into α-tin at low temperatures caused the death of R. Scott's expedition to the South Pole, who lost all fuel, as it was stored in sealed tanks tin), stable at t<14°С, серый порошок.

· Β-tin, or white tin (t = 14 - 161 ° C) is a very soft metal, but harder than lead, amenable to casting and soldering. It is used in alloys such as tinplate (tinned iron).

Electrochemical series of voltages of metals and its two rules

The arrangement of atoms in a row according to their reactivity can be represented as follows:

Li, K, Ca, Na, Mg, Al, Mn, Zn, Fe, Ni, Sn, Pb,H2 , Сu, Hg, Ag, Pt, Au.

The position of an element in the electrochemical series shows how easily it forms ions in an aqueous solution, i.e., its reactivity. The reactivity of elements depends on the ability to accept or donate electrons involved in the formation of a bond.

1st rule of a series of voltages

If the metal is in this row before hydrogen, it is able to displace it from acid solutions, if after hydrogen, then not.

For instance, Zn, Mg, Al gave a substitution reaction with acids (they are in the series of voltages up to H), a Cu no (she after H).

2nd rule of a series of voltages

If the metal is in the series of stresses up to the metal of the salt, then it is able to displace this metal from the solution of its salt.

For example, CuSO4 + Fe = FeSO4 + Cu.

In such cases, the position of the metal before or after hydrogen it may not matter, it is important that the reacting metal precedes the metal forming the salt:

Cu + 2AgNO3 = 2Ag + Cu (NO3) 2.

General chemical properties of metals

In chemical reactions, metals are reducing agents (they donate electrons).

Interaction with simple substances.

1. With halogens, metals form salts - halides:

Mg + Cl2 = MgCl2;

Zn + Br2 = ZnBr2.

2. Metals form oxides with oxygen:

4Na + O2 = 2 Na2O;

2Cu + O2 = 2CuO.

3. With sulfur, metals form salts - sulfides:

4. With hydrogen, the most active metals form hydrides, for example:

Ca + H2 = CaH2.

5.with carbon, many metals form carbides:

Ca + 2C = CaC2.

Interaction with complex substances

1. Metals at the beginning of a series of voltages (from lithium to sodium), under normal conditions, displace hydrogen from water and form alkalis, for example:

2Na + 2H2O = 2NaOH + H2.

2. Metals located in the series of voltages up to hydrogen interact with dilute acids (НCl, Н2SO4, etc.), as a result of which salts are formed and hydrogen is released, for example:

2Al + 6HCl = 2AlCl3 + 3H2.

3. Metals interact with solutions of salts of less active metals, as a result of which a salt of a more active metal is formed, and less active metal is released in a free form, for example:

CuSO4 + Fe = FeSO4 + Cu.

Metals in nature.

Finding metals in nature.

Most metals are found in nature in the form of various compounds: active metals are found only in the form of compounds; low-activity metals - in the form of compounds and in free form; noble metals (Ag, Pt, Au ...) in free form.

Native metals are usually found in small quantities in the form of grains or inclusions in rocks. Rarely, there are also quite large pieces of metal - nuggets. Many metals in nature exist in a bound state in the form of chemical natural compounds - minerals... Very often these are oxides, for example, iron minerals: red iron ore Fe2O3, brown iron ore 2Fe2O3 ∙ 3H2O, magnetic iron ore Fe3O4.

Minerals are part of rocks and ores. Ores are called natural formations containing minerals, in which metals are present in quantities that are technologically and economically suitable for the production of metals in industry.

According to the chemical composition of the mineral included in the ore, there are oxide, sulfide and other ores.

Usually, before obtaining metals from ore, it is preliminarily enriched - empty rock, impurities are separated, as a result, a concentrate is formed, which serves as a raw material for metallurgical production.

Methods for obtaining metals.

The production of metals from their compounds is the task of metallurgy. Any metallurgical process is a process of reduction of metal ions with the help of various reducing agents, as a result of which metals are obtained in a free form. Depending on the method of carrying out the metallurgical process, pyrometallurgy, hydrometallurgy and electrometallurgy are distinguished.

Pyrometallurgy Is the production of metals from their compounds at high temperatures using various reducing agents: carbon, carbon monoxide (II), hydrogen, metals (aluminum, magnesium), etc.

Examples of metal recovery

ZnO + C → Zn + CO2;

Carbon monoxide:

Fe2O3 + 3CO → 2Fe + 3CO2;

Hydrogen:

WO3 + 3H2 → W + 3H2O;

CoO + H2 → Co + H2O;

Aluminum (alumothermy):

4Al + 3MnO2 → 2Al2O3 + 3Mn;

Cr2O3 + 2Al = 2Al2O3 + 2Cr;

Magnesium:

TiCl4 + 2Mg = Ti + 2MgCl2.

Hydrometallurgy- This is the production of metals, which consists of two processes: 1) the natural compound of the metal dissolves in acid, resulting in a solution of the metal salt; 2) from the resulting solution, this metal is displaced by a more active metal. For instance:

1.2CuS + 3О2 = 2CuO + 2SО2.

CuO + H2SO4 = CuSO4 + H2O.

2. CuSO4 + Fe = FeSO4 + Cu.

Electrometallurgy- This is the production of metals by electrolysis of solutions or melts of their compounds. Electric current plays the role of a reducing agent in the electrolysis process.

General characteristics of the metals of the IA group.

The metals of the main subgroup of the first group (IA-group) include lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), francium (Fr). These metals are called alkali metals, since they and their oxides form alkalis when interacting with water.

Alkali metals are s-elements. On the outer electron layer, metal atoms have one s-electron (ns1).

Potassium, sodium - simple substances

Alkali metals in ampoules:
a - cesium; b - rubidium; c - potassium; g - sodium

Basic information about the elements of the IA group

	Li lithium	Na sodium	K potassium	Rb rubidium	Cs cesium	Fr france
Atomic number
Oxidation state
Basic natural compounds	Li2O · Al2O3 · 4SiO2 (spodumene); LiAl (PO4) F, LiAl (PO4) OH (amblygonite)	NaCl (table salt); Na2SO4 10H2O (Glauber's salt, mirabiite); КCl NaCl (sylvite)	KCl (sylvinite), KCl NaCl (sylvinite); K (potassium feldspar, orthogonal); KCl MgCl2 6H2O (carnallite) - found in plants	As an isoamorphic impurity in potassium minerals - sylvinite and carnallite	4Cs2O · 4Al2O3 · 18 SiO2 · 2H2O (semi-cyt); companion of potassium minerals	Α-decay product of actinium

Physical properties

Potassium and sodium are soft silvery metals (cut with a knife); ρ (K) = 860 kg / m3, Tm (K) = 63.7 ° C, ρ (Na) = 970 kg / m3, Tm (Na) = 97.8 ° C. They have high heat and electrical conductivity, paint the flame in characteristic colors: K - in a pale violet color, Na - in yellow.

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Interaction with complex substances:

1.2Na + 2H2O → 2NaOH + H2.

2. 2Na + Na2О2 → 2Na2О.

3.2Na + 2НCl → 2NaCl + Н2.

Pulp and paper industry "href =" / text / category / tcellyulozno_bumazhnaya_promishlennostmz / "rel =" bookmark "> production of paper, artificial fabrics, soap, for cleaning oil pipelines, in the production of artificial fibers, in alkaline batteries.

Finding metal compoundsIAgroups in nature.

Salt ― NaCl- sodium chloride, NaNO3- sodium nitrate (Chilean nitrate), Na2CO3- sodium carbonate (soda), NaHCO3- sodium bicarbonate (baking soda), Na2SO4- sodium sulfate, Na2SO4 10H2O- Glauber's salt, KCl- potassium chloride, KNO3- potassium nitrate (potassium nitrate), K2SO4- potassium sulfate, К2СО3- potassium carbonate (potash) - crystalline ionic substances, almost all soluble in water. Sodium and potassium salts exhibit the properties of medium salts:

2NaCl (solid) + Н2SO4 (conc.) → Na2SO4 + 2НCl;

КCl + AgNo3 → KNO3 + AgCl ↓;

Na2CO3 + 2HCl → NaCl + CO2 + H2O;

K2CO3 + H2O ↔ KHCO3 + KOH;

СО32- + Н2О ↔ HCO3- + OH - (alkaline medium, pH< 7).

Table salt crystals

Salt mine

Na2CO3 serves for the production of paper, soap, glass;

NaHCO3- in medicine, cooking, in the production of mineral waters, in fire extinguishers;

К2СО3- to obtain liquid soap and glass;

Potash - potassium carbonate

NaNO3, KNO3, KCl, K2SO4- the most important potash fertilizers.

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Sea salt contains 90-95% NaCl (sodium chloride) and up to 5% of other minerals: magnesium salts, calcium salts, potassium salts, manganese salts, phosphorus salts, iodine salts, etc. All together over 40 useful elements of the periodic table - all this exists in sea water.

Dead Sea

There is something extraordinary, almost fantastic in him. In the eastern lands, even the tiniest trickle of moisture is a source of life, gardens bloom there, cereals ripen. But this water kills all living things.

Many peoples have visited these shores: Arabs, Jews, Greeks, Romans; each of them called this huge lake in their own language, but the meaning of the name was the same: dead, perilous, lifeless.

We stood on a deserted shore, the dull look of which evoked sadness: a dead land - no grass, no birds. On the other side of the lake, reddish mountains rose steeply from the green water. Bare, wrinkled slopes. It seemed that some force tore off their natural cover, and the muscles of the earth were exposed.

We decided to take a dip, but the water turned out to be cold, we just washed ourselves with thick water, flowing like a cool brine. After a few minutes, the face and hands were covered with a white coating of salt, and an unbearably bitter taste remained on the lips, from which it was impossible to get rid of it for a long time. You cannot drown in this sea: thick water itself keeps a person on the surface.

Sometimes a fish swims from Jordan to the Dead Sea. She dies in a minute. We found one such fish washed ashore. She was as hard as a stick in a tough, salty shell.
This sea can become a source of wealth for the people. After all, this is a gigantic storehouse of mineral salts.

Each liter of Dead Sea water contains 275 grams of potassium, sodium, bromine, magnesium, calcium salts. Mineral reserves are estimated here at 43 billion tons. Bromine and potash can be mined extremely cheaply, and there is nothing to limit the scale of production. The country possesses huge reserves of phosphates, which are in great demand on the world market, and their negligible amount is mined.

General characteristics of the elements of the IIA-group.

The metals of the main subgroup of the second group (IIA-group) include beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), radium (Ra). These metals are called alkaline earth metals, since their hydroxides Ме (ОН) 2 have alkaline properties, and their oxides МеО are similar in their refractoriness to the oxides of heavy metals, formerly called "earths".

Alkaline earth metals are s-elements. On the outer electron layer, metal atoms have two s-electrons (ns2).

Basic information about the elements of IIA-group

	Be beryllium	Mg magnesium	Ca calcium	Sr strontium	Ba barium	Ra radium
Atomic number
The structure of the outer electron shells of atoms	where n = 2, 3, 4, 5, 6, 7, n is the number of the period
Oxidation state
Basic natural compounds	3BeO Al2O3 6SiO2 (beryl); Be2SiO4 (phenakite)	2MgO SO2 (olivine); MgCO3 (magnesite); MgCO3 CaCO3 (dolomite); MgCl2 KCl 6H2O (carnallite)	CaCO3 (calcite), СaF2― fluorite, СaO · Al2O3 · 6SiO2 (anorthite); CaSO4 2H2O (gypsum); MgCO3 CaCO3 (dolomite), Ca3 (PO4) 2 - phosphorite, Ca5 (PO4) 3X (X = F, Cl, OH) - apatite	SrCO3 (stron cyanite), SrSO4 (celestine)	BaCO3 (baterite) BaSO4 (barite, heavy spar)	As part of uranium ores

Alkaline earth- light silver-white metals. Strontium has a golden hue, much harder than alkali metals. Barium is similar in softness to lead. In air at ordinary temperatures, the surface of beryllium and magnesium is covered with a protective oxide film. Alkaline earth metals actively interact with atmospheric oxygen, so they are stored under a layer of kerosene or in sealed vessels, like alkali metals.

Calcium is a simple substance

Physical properties

Natural calcium is a mixture of stable isotopes. The most common calcium is 97%). Calcium is a silvery white metal; ρ = 1550 kg / m3, Tm = 839 ° C. Colors the flame orange-red.

Chemical properties

Interaction with simple substances (non-metals):

1.With halogens: Ca + Cl2 → CaCl2 (calcium chloride).

2.With carbon: Ca + 2C → CaC2 (calcium carbide).

3. With hydrogen: Ca + H2 → CaH2 (calcium hydride).

Salt: CaCO3 calcium carbonate is one of the most widespread compounds on Earth: chalk, marble, limestone. The most important of these minerals is limestone. He himself is an excellent building stone, in addition, he is a raw material for producing cement, slaked lime, glass, etc.

Lime crushed stone strengthens roads, and powder reduces soil acidity.

Natural chalk represents the remains of ancient animal shells. It is used as school crayons, in toothpastes, for the production of paper and rubber.

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Physical properties

Iron is a silvery-white or gray metal, solid, with high ductility, heat and electrical conductivity, refractory; ρ = 7874 kg / m3, Tm = 1540 ° C. Unlike other metals, iron is capable of magnetization, it has ferromagnetism.

Chemical properties

Iron interacts with both simple and complex substances.

Interaction of iron with oxygen

a) when heated (combustion), b) when n. at. (corrosion)

Iron chemical properties

Under n. at.	When heated
Reaction	3FeSO4 + 2K3 = Fe32 ↓ + 3K2SO4 (turbulene blue - dark blue sediment).	1. 4FeCl3 + 3K4 = Fe43 ↓ + 12KCl (Prussian blue - dark blue precipitate). 2. FeCl3 + 3NH4CNS ⇆ Fe (CNS) 3 + 3NH4Cl (blood-red Fe thiocyanate + ammonia).

The biological role of iron

Biochemists reveal the huge role of iron in the life of plants, animals and humans. As part of hemoglobin, iron causes the red color of this substance, which, in turn, determines the color of the blood. The body of an adult contains 3 g of iron, of which 75% are part of hemoglobin, due to which the most important biological process, respiration, is carried out. Iron is also essential for plants. It participates in the oxidative processes of protoplasm, during plant respiration and in the formation of chlorophyll, although it is not itself a part of it. Iron has long been used in medicine to treat anemia, with exhaustion, loss of strength.

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Slide captions:

The position of metals in the Periodic Table of D.I. Mendeleev. Features of the structure of atoms, properties.

The purpose of the lesson: 1. On the basis of the position of metals in the PSCE, come to an understanding of the structural features of their atoms and crystals (metal chemical bonds and crystal metal lattice). 2. To generalize and expand knowledge about the physical properties of metals and their classifications. 3. Develop the ability to analyze, draw conclusions based on the position of metals in the periodic table of chemical elements.

COPPER I'm going on small coins, I like to ring in bells, They erect a monument to me for this And they know: my name is….

IRON To plow and build - he can do everything, if the coal will help him in that ...

Metals are a group of substances with common properties.

The metals are elements of I-III groups of the main subgroups, and IV-VIII groups of secondary subgroups I group II group III group IV group V group VI group VII group VIII group Na Mg Al Ti V Cr Mn Fe

Of the 109 elements of PSCE, 85 are metals: they are highlighted in blue, green and pink (except for H and He)

The position of an element in the PS reflects the structure of its atoms. POSITION OF THE ELEMENT IN THE PERIODIC SYSTEM STRUCTURE OF ITS ATOMS Ordinal number of the element in the periodic system Nuclear charge of the atom Total number of electrons Group number Number of electrons at the external energy level. Highest valence of an element, oxidation state Period number Number of energy levels. The number of sublevels at the external energy level

Sodium atom model

The electronic structure of the sodium atom

Task 2. Make a diagram of the electronic structure of the aluminum and calcium atoms in the notebook yourself, following the example with the sodium atom.

Conclusion: 1. Metals are elements that have 1-3 electrons at the external energy level, less often 4-6. 2. Metals are chemical elements whose atoms donate electrons to the outer (and sometimes pre-outer) electronic layer, turning into positive ions. Metals are reducing agents. This is due to the small number of electrons in the outer layer, the large radius of the atoms, as a result of which these electrons are weakly confined to the nucleus.

A metallic chemical bond is characterized by: - ​​delocalization of the bond, because a relatively small number of electrons simultaneously bind many nuclei; - valence electrons move freely over the entire piece of metal, which is generally electrically neutral; - the metal bond does not have directionality and saturation.

Crystalline lattices of metals

Video information about metal crystals

The properties of metals are determined by the structure of their atoms. Metal property Property property hardness All metals, except mercury, are solids under normal conditions. The mildest are sodium, potassium. They can be cut with a knife; the hardest chrome - scratches glass. density Metals are divided into light (density 5g / cm) and heavy (density greater than 5g / cm). fusibility Metals are divided into low-melting and refractory electrical conductivity, thermal conductivity Chaotically moving electrons under the influence of electric voltage acquire directional motion, resulting in an electric current. metallic luster Electrons filling the interatomic space reflect light rays, and do not transmit plasticity like glass. Mechanical action on a crystal with a metal lattice only causes displacement of atomic layers and is not accompanied by bond breaking, and therefore the metal is characterized by high plasticity.

Check the assimilation of knowledge in the lesson by testing 1) Electronic formula of calcium. А) 1S 2 2S 2 2Р 6 3S 1 B) 1S 2 2S 2 2 Р 6 3 S 2 C) 1S 2 2S 2 2 Р 6 3 S 2 3S 6 4S 1 D) 1S 2 2S 2 2 Р 6 3 S 2 3 R 6 4 S 2

Test tasks 2 and 3 2) The electronic formula 1S 2 2S 2 2P 6 3S 2 3P 6 4S 2 has an atom: a) Na b) Ca c) Cu d) Zn 3) Electrical conductivity, metallic luster, plasticity, density of metals are determined: a ) the mass of atoms b) the melting point of metals c) the structure of metal atoms d) the presence of unpaired electrons

Test items 4 and 5 4) Metals interacting with non-metals exhibit properties a) oxidizing; b) restorative; c) both oxidizing and reducing; d) do not participate in redox reactions; 5) In the periodic table, typical metals are located in: a) the upper part; b) the lower part; in the upper right corner; d) lower left corner;

Correct answers Task number Correct answer option 1 D 2 B 3 C 4 B 5 D

Preview:

The purpose and objectives of the lesson:

1. On the basis of the position of metals in the PSCE, lead students to an understanding of the structural features of their atoms and crystals (metallic chemical bonds and crystalline metal lattice), to study the general physical properties of metals. Review and summarize knowledge about chemical bonding and metal crystal lattice.
2. To develop the ability to analyze, draw conclusions about the structure of atoms based on the position of metals in the PSCE.
3. Develop the ability to master chemical terminology, clearly formulate and express your thoughts.
4. To foster independent thinking in the course of educational activities.
5. To generate interest in the future profession.

Lesson form:

combined lesson with presentation

Methods and techniques:

Story, conversation, video demonstration of the types of crystal lattices of metals, test, drawing up diagrams of the electronic structure of atoms, demonstration of a collection of samples of metals and alloys.

Equipment:

1. Table “Periodic table of chemical elements of D.I. Mendeleev ";
2. Presentation of the lesson on electronic media.
3. Collection of samples of metals and alloys.
4. Projector.
5. Cards with the table "Characteristics of the structure of the atom by position in the PSCE"
   

DURING THE CLASSES

I. Organizational moment of the lesson.

II. Statement and announcement of the topic of the lesson, its goals and objectives.

Slide 1-2

III. Learning new material.

Teacher: Man has used metals since ancient times. Briefly about the history of the use of metals.

1 student message. Slide 3

In the beginning there was a copper age.

By the end of the Stone Age, man discovered the possibility of using metals for the manufacture of tools. The first such metal was copper.

The period of the spread of copper tools is called Chalcolithic or Chalcolithic , which translated from Greek means "copper". Copper was processed using stone tools using the cold forging method. Copper nuggets were turned into products under heavy hammer blows. At the beginning of the Copper Age, only soft tools, jewelry, and household items were made of copper. It was with the discovery of copper and other metals that the profession of a blacksmith began to emerge.

Later, casting appeared, and then people began to add tin or antimony to copper, to make bronze, more durable, strong, fusible.

Student message 2. Slide 3

Bronze - an alloy of copper and tin. The chronological boundaries of the Bronze Age date back to the beginning of the 3rd millennium BC. before the beginning of the 1st millennium BC

Student message 3. Slide 4

The third and final period of the primitive era is characterized by the spread of iron metallurgy and iron tools and marks the Iron Age. In its modern meaning, this term was introduced in the middle of the 9th century by the Danish archaeologist K. Yu. Thomson and soon spread in literature along with the terms “Stone Age” and “Bronze Age”.

Unlike other metals, iron, except for meteorite, is almost never found in its pure form. Scientists assume that the first iron that fell into the hands of man was of meteorite origin, and it is not for nothing that the iron is called a "heavenly stone." The largest meteorite found in Africa, it weighed about sixty tons. And in the ice of Greenland, they found an iron meteorite weighing thirty-three tons.

And now the Iron Age continues. Indeed, at present, iron alloys make up almost 90% of all metals and metal alloys.

Teacher.

Gold and silver - precious metals are currently used for the manufacture of jewelry, as well as parts in the electronics, aerospace industry, and shipbuilding. Where can these metals be used in shipping? The exceptional importance of metals for the development of society is due, of course, to their unique properties. Name these properties.

Demonstrate to students a collection of metal samples.

Students name such properties of metals as electrical conductivity and thermal conductivity, characteristic metallic luster, plasticity, hardness (except for mercury), etc.

The teacher asks the students a key question: what is the reason for these properties?

Expected response:properties of substances are due to the structure of molecules and atoms of these substances.

Slide 5. So, metals are a group of substances with common properties.

Demonstration of presentation.

Teacher: Metals are elements of 1-3 groups of main subgroups, and elements of 4-8 groups of secondary subgroups.

Slide 6. Task 1 ... On your own, using PSCE, add the representatives of the groups, which are metals, in the notebook.

							VIII

Hearing students' answers selectively.

Teacher: the metals will be the elements located in the lower left corner of the PSCE.

The teacher emphasizes that all elements located below the B - At diagonal, even those with 4 electrons (Ge, Sn, Pb), 5 electrons (Sb, Bi), 6 electrons (Po) on the outer layer, will be metals in PSCE, since they have a large radius.

Thus, 85 out of 109 elements of PSChE are metals. Slide number 7

Teacher: the position of the element in the PSCE reflects the atomic structure of the element. Using the tables that you received at the beginning of the lesson, we characterize the structure of the sodium atom by its position in the PSCE.
Demonstration of slide 8.

What is a sodium atom? Look at the approximate model of the sodium atom, in which you can see the nucleus and electrons moving in orbits.

Demonstration of Slide 9.Sodium atom model.

Let me remind you how a diagram of the electronic structure of an atom of an element is drawn up.

Demonstration of slide 10.You should have the following diagram of the electronic structure of the sodium atom.

Slide 11. Task 2. Make a diagram of the electronic structure of the calcium and aluminum atom in the notebook yourself, following the example with the sodium atom.

The teacher checks the work in the notebook.

What conclusion can be drawn about the electronic structure of metal atoms?

On the external energy level, 1-3 electrons. We remember that entering into chemical compounds, atoms strive to restore the full 8-electron shell of the external energy level. For this, metal atoms easily donate 1-3 electrons from the external level, turning into positively charged ions. At the same time, they show restorative properties.

Demonstration of slide 12. Metals - these are chemical elements, the atoms of which donate electrons of the outer (and sometimes pre-outer) electronic layer, turning into positive ions. Metals are reducing agents. This is due to the small number of electrons in the outer layer, the large radius of the atoms, as a result of which these electrons are weakly confined to the nucleus.

Let's consider simple substances - metals.

Demonstration of slide 13.

First, we summarize information about the type of chemical bond formed by metal atoms and the structure of the crystal lattice

1. a relatively small number of electrons simultaneously bind many nuclei, the bond is delocalized;
2. valence electrons move freely over the entire piece of metal, which is generally electrically neutral;
3. the metallic bond does not have directionality and saturation.

Demonstration

Slide 14 " Types of crystal lattices of metals»

Slide 15 Video of the crystal lattice of metals.

The students conclude that in accordance with this particular structure, metals are characterized by general physical properties.

The teacher emphasizes that the physical properties of metals are determined precisely by their structure.

Slide 16 The properties of metals are determined by the structure of their atoms.

a) hardness - all metals except mercury, solids under normal conditions. The mildest are sodium, potassium. They can be cut with a knife; the hardest chrome - scratches glass (demo).

b) density - metals are divided into light (5g / cm) and heavy (more than 5g / cm) (demonstration).

c) fusibility - metals are divided into fusible and refractory (demonstration).

G) electrical conductivity, thermal conductivitymetals due to their structure. Chaotically moving electrons under the action of an electric voltage acquire a directional movement, as a result of which an electric current arises.

As the temperature rises, the amplitude of the motion of atoms and ions located in the nodes of the crystal lattice increases sharply, and this interferes with the movement of electrons, and the electrical conductivity of metals decreases.

It should be noted that in some non-metals, with an increase in temperature, the electrical conductivity increases, for example, in graphite, while with an increase in temperature, some covalent bonds are destroyed, and the number of freely moving electrons increases.

e) metallic luster- electrons filling the interatomic space reflect light rays, and do not transmit, like glass.

Therefore, all metals in the crystalline state have a metallic luster. For most metals, all rays of the visible part of the spectrum are equally scattered, so they have a silvery-white color. Only gold and copper absorb to a large extent short wavelengths and reflect long wavelengths of the light spectrum, therefore they have yellow light. The most brilliant metals are mercury, silver, palladium. In the powder, all metals, except for AI and Mg, lose their luster and have a black or dark gray color.

f) plasticity ... Mechanical action on a crystal with a metal lattice only causes displacement of atomic layers and is not accompanied by bond breaking, and therefore the metal is characterized by high plasticity.

IV. Consolidation of the studied material.

Teacher: we examined the structure and physical properties of metals, their position in the periodic table of chemical elements of D.I. Mendeleev. Now, to consolidate, we suggest performing a test.

Slides 15-16-17.

1) Electronic formula of calcium.

1. a) 1S 2 2S 2 2P 6 3S 1
2. b) 1S 2 2S 2 2P 6 3S 2
3. c) 1S 2 2S 2 2P 6 3S 2 3S 6 4S 1
4. d) 1S 2 2S 2 2P 6 3S 2 3P 6 4S 2

2) Electronic formula 1S 2 2S 2 2P 6 3S 2 3P 6 4S 2 has an atom:

1. a) Na
2. b) Ca
3. c) Сu
4. d) Zn

3) Electrical conductivity, metallic luster, plasticity, density of metals are determined by:

1. a) the mass of metal
2. b) the melting point of metals
3. c) the structure of metal atoms
4. d) the presence of unpaired electrons

4) Metals, when interacting with non-metals, exhibit properties

1. a) oxidative;
2. b) restorative;
3. c) both oxidizing and reducing;
4. d) do not participate in redox reactions;

5) In the periodic table, typical metals are located in:

1. a) upper part;
Vi. Homework.

The structure of metal atoms, their physical properties




Introduction




Metals are simple substances with characteristic properties under normal conditions: high electrical conductivity and thermal conductivity, the ability to reflect light well (which determines their shine and opacity), the ability to take the desired shape under the influence of external forces (plasticity). There is another definition of metals - these are chemical elements characterized by the ability to donate external (valence) electrons.

Of all the known chemical elements, about 90 are metals. Most inorganic compounds are metal compounds.

There are several types of metal classification. The clearest is the classification of metals in accordance with their position in the periodic table of chemical elements - chemical classification.

If, in the "long" version of the periodic table, draw a straight line through the elements boron and astatine, then metals will be located to the left of this line, and non-metals to the right of it.

From the point of view of atomic structure, metals are subdivided into intransitional and transitional. Non-transition metals are located in the main subgroups of the periodic system and are characterized by the fact that in their atoms there is a successive filling of the electronic levels s and p. Intransitional metals include 22 elements of the main subgroups a: Li, Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba, Ra, Al, Ga, In, Tl, Ge, Sn, Pb, Sb, Bi, Po.

Transition metals are located in side subgroups and are characterized by the filling of d - or f-electronic levels. The d-elements include 37 metals of side subgroups b: Cu, Ag, Au, Zn, Cd, Hg, Sc, Y, La, Ac, Ti, Zr, Hf, Rf, V, Nb, Ta, Db, Cr, Mo , W, Sg, Mn, Tc, Re, Bh, Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, Pt, Hs, Mt.

The f-elements include 14 lanthanides (Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Du, Ho, Er, Tm, Yb, Lu) and 14 actinides (Th, Pa, U, Np, Pu, Am, Cm, Bk, Cf, Es, Fm, Md, No, Lr).

Among the transition metals, there are also rare earth metals (Sc, Y, La and lanthanides), platinum metals (Ru, Rh, Pd, Os, Ir, Pt), transuranic metals (Np and elements with a higher atomic mass).

In addition to the chemical, there is also, although not generally accepted, but long established technical classification of metals. It is not as logical as a chemical one - it is based on one or another practically important feature of a metal. Iron and alloys based on it are classified as ferrous metals, all other metals are classified as non-ferrous. Distinguish between light (Li, Be, Mg, Ti, etc.) and heavy metals (Mn, Fe, Co, Ni, Cu, Zn, Cd, Hg, Sn, Pb, etc.), as well as groups of refractory (Ti, Zr , Hf, V, Nb, Ta, Cr, Mo, W, Re), precious (Ag, Au, platinum metals) and radioactive (U, Th, Np, Ru, etc.) metals. Scattered (Ga, Ge, Hf, Re, etc.) and rare (Zr, Hf, Nb, Ta, Mo, W, Re, etc.) metals are also distinguished in geochemistry. As you can see, there are no clear boundaries between the groups.

History reference




Despite the fact that the life of human society without metals is impossible, no one knows for sure when and how a person first began to use them. The most ancient writings that have come down to us tell of primitive workshops in which metal was smelted and products were made from it. This means that man mastered metals earlier than writing. Digging up ancient settlements, archaeologists find tools of labor and hunting that people used in those distant times - knives, axes, arrowheads, needles, fish hooks and much more. The more ancient the settlements, the coarser and more primitive were the products of human hands. The most ancient metal products were found during excavations of settlements that existed about 8 thousand years ago. These were mainly jewelry made of gold and silver, and arrowheads and spearheads made of copper.

The Greek word "metallon" originally meant mines, mines, hence the term "metal" originated. In ancient times, it was believed that there were only 7 metals: gold, silver, copper, tin, lead, iron and mercury. This number correlated with the number of then known planets - the Sun (gold), the Moon (silver), Venus (copper), Jupiter (tin), Saturn (lead), Mars (iron), Mercury (mercury) (see figure). According to alchemical concepts, metals originated in the bowels of the earth under the influence of the rays of the planets and gradually improved, turning into gold.

Man first mastered native metals - gold, silver, mercury. The first artificially obtained metal was copper, then it was possible to master the production of an alloy of copper with brine - bronze and only later - iron. In 1556, a book by the German metallurgist G. Agricola "On mining and metallurgy" was published in Germany - the first detailed guide to the production of metals that has come down to us. True, at that time, lead, tin and bismuth were still considered varieties of the same metal. In 1789, the French chemist A. Lavoisier, in his manual on chemistry, gave a list of simple substances, which included all the metals known then - antimony, silver, bismuth, cobalt, tin, iron, manganese, nickel, gold, platinum, lead, tungsten and zinc. With the development of methods of chemical research, the number of known metals began to increase rapidly. In the 18th century. 14 metals were discovered, in the 19th century. - 38, in the 20th century. - 25 metals. In the first half of the 19th century. satellites of platinum were discovered, alkali and alkaline earth metals were obtained by electrolysis. In the middle of the century, cesium, rubidium, thallium and indium were discovered by spectral analysis. The existence of metals predicted by D.I.Mendeleev on the basis of his periodic law (these are gallium, scandium and germanium) was brilliantly confirmed. The discovery of radioactivity at the end of the 19th century. entailed a search for radioactive metals. Finally, by the method of nuclear transformations in the middle of the 20th century. radioactive metals that do not exist in nature were obtained, in particular transuranium elements.




Physical and chemical properties of metals.




All metals are solids (except for mercury, which is liquid under normal conditions); they differ from non-metals in a special type of bond (metallic bond). Valence electrons are weakly bound to a specific atom, and inside each metal there is a so-called electron gas. Most metals have a crystalline structure, and the metal can be thought of as a "rigid" crystal lattice of positive ions (cations). These electrons can more or less move around the metal. They compensate for the repulsive forces between the cations and, thus, bind them into a compact body.

All metals have high electrical conductivity (i.e., they are conductors, as opposed to non-metallic dielectrics), especially copper, silver, gold, mercury and aluminum; the thermal conductivity of metals is also high. A distinctive property of many metals is their ductility (malleability), as a result of which they can be rolled into thin sheets (foil) and drawn into a wire (tin, aluminum, etc.), however, there are also quite brittle metals (zinc, antimony, bismuth).

In industry, not pure metals are often used, but their mixtures, called alloys. In an alloy, the properties of one component usually complement the properties of the other. So, copper has a low hardness and is of little use for the manufacture of machine parts, while copper-zinc alloys, called brass, are already quite hard and are widely used in mechanical engineering. Aluminum has good ductility and sufficient lightness (low density), but too soft. On its basis, ayuralumin alloy (duralumin) is prepared, containing copper, magnesium and manganese. Duralumin, without losing the properties of its aluminum, acquires a high hardness and therefore is used in aviation technology. Alloys of iron with carbon (and additives of other metals) are well-known cast iron and steel.

Metals are very different in density: for lithium it is almost half that of water (0.53 g / cm3), and for osmium it is more than 20 times higher (22.61 g / cm3). Metals also differ in hardness. The softest - alkali metals, they are easily cut with a knife; the hardest metal - chrome - cuts glass. The difference in the melting temperatures of metals is great: mercury is a liquid under normal conditions, cesium and gallium melt at the temperature of a human body, and the most refractory metal, tungsten, has a melting point of 3380 ° C. Metals with a melting point above 1000 ° C are referred to as refractory metals, below - to low-melting metals. At high temperatures, metals are capable of emitting electrons, which is used in electronics and thermoelectric generators to directly convert thermal energy into electrical energy. Iron, cobalt, nickel and gadolinium, after placing them in a magnetic field, are able to constantly maintain a state of magnetization.

Metals also have some chemical properties. Metal atoms relatively easily donate valence electrons and transform into positively charged ions. Therefore, metals are reducing agents. This, in fact, is their main and most general chemical property.

Obviously, metals as reducing agents will react with various oxidizing agents, among which there may be simple substances, acids, salts of less active metals and some other compounds. Compounds of metals with halogens are called halides, with sulfur - sulfides, with nitrogen - nitrides, with phosphorus - phosphides, with carbon - carbides, with silicon - silicides, with boron - borides, with hydrogen - hydrides, etc. Many of these compounds found important applications in new technology. For example, metal borides are used in radio electronics, as well as in nuclear technology as materials for regulating neutron radiation and protecting against it.

Under the action of concentrated oxidizing acids, a stable oxide film is also formed on some metals. This phenomenon is called passivation. So, in concentrated sulfuric acid such metals as Be, Bi, Co, Fe, Mg, and Nb are passivated (and do not react with it), and in concentrated nitric acid - metals Al, Be, Bi, Co, Cr, Fe, Nb, Ni, Pb, Th and U.

The more to the left the metal is located in this row, the more reducing properties it possesses, that is, it oxidizes more easily and passes in the form of a cation into a solution, but it is more difficult to restore from a cation to a free state.

One non-metal, hydrogen, is placed in a series of voltages, since this makes it possible to determine whether a given metal will react with acids - non-oxidizing agents in an aqueous solution (more precisely, it will be oxidized by hydrogen cations H +). For example, zinc reacts with hydrochloric acid, since in the series of voltages it stands to the left (up to) hydrogen. On the contrary, silver is not transferred into solution by hydrochloric acid, since it stands in the series of voltages to the right (after) of hydrogen. Metals behave similarly in dilute sulfuric acid. Metals in the series of stresses after hydrogen are called noble metals (Ag, Pt, Au, etc.)

An undesirable chemical property of metals is their electrochemical corrosion, i.e., active destruction (oxidation) of the metal in contact with water and under the influence of oxygen dissolved in it (oxygen corrosion). For example, corrosion of iron products in water is widely known.

Particularly corrosive can be the place of contact of two dissimilar metals - contact corrosion. A galvanic pair arises between one metal, such as Fe, and another metal, such as Sn or Cu, placed in water. The flow of electrons goes from the more active metal, which is to the left in the series of voltages (Fe), to the less active metal (Sn, Cu), and the more active metal is destroyed (corroded).

It is because of this that the tinned surface of cans (tin-coated iron) rusts when stored in a humid atmosphere and carelessly handling them (iron quickly collapses after the appearance of even a small scratch that allows iron to come into contact with moisture). On the contrary, the galvanized surface of an iron bucket does not rust for a long time, because even in the presence of scratches, it is not iron that corrodes, but zinc (a more active metal than iron).

Corrosion resistance for a given metal increases when it is coated with a more active metal or when they are fused; for example, plating iron with chromium or making iron-chromium alloys eliminates the corrosion of iron. Chromium-plated iron and chrome-containing steels (stainless steels) have high corrosion resistance.

General methods of obtaining metals:

Electrometallurgy, i.e. the production of metals by electrolysis of melts (for the most active metals) or solutions of their salts;

Pyrometallurgy, i.e. the reduction of metals from their ores at high temperatures (for example, the production of iron using a blast furnace process);

Hydrometallurgy, i.e. the separation of metals from solutions of their salts with more active metals (for example, obtaining copper from a CuSO4 solution by displacing zinc, iron

or aluminum).

In nature, metals are sometimes found in free form, for example, native mercury, silver and gold, and more often in the form of compounds (metal ores). The most active metals, of course, are present in the earth's crust only in bound form.





Lithium (from the Greek. Lithos - stone), Li, a chemical element of subgroup Ia of the periodic system; atomic number 3, atomic mass 6, 941; refers to alkali metals.

The lithium content in the earth's crust is 6.5-10-3% by weight. It is found in more than 150 minerals, of which about 30 are actually lithium. The main minerals are: spodumene LiAl, lepidolite KLi1.5 Al1.5 (F, 0H) 2 and petalite (LiNa). The composition of these minerals is complex, many of them belong to the class of aluminosilicates, very widespread in the earth's crust. Promising sources of raw materials for lithium production are brines (brine) of saline deposits and groundwater. The largest deposits of lithium compounds are located in Canada, USA, Chile, Zimbabwe, Brazil, Namibia and Russia.

Interestingly, the mineral spodumene occurs naturally in the form of large crystals weighing several tons. At the Etta mine in the United States, they found a crystal in the shape of a needle 16 m long and weighing 100 tons.

The first information about lithium dates back to 1817. The Swedish chemist A. Arfvedson, while analyzing the mineral petalite, discovered an unknown alkali in it. Arfvedson's teacher J. Berzelius gave it the name "lithion" (from the Greek liteo-stone), because, unlike potassium and sodium hydroxides, which were obtained from plant ash, a new alkali was found in the mineral. He also called the metal, which is the "base" of this alkali, lithium. In 1818 the English chemist and physicist G. Davy obtained lithium by electrolysis of LiOH hydroxide.

Properties. Lithium is a silvery white metal; t. pl. 180.54 ° C, bp 1340 "C; the lightest of all metals, its density is 0.534 g / cm, it is 5 times lighter than aluminum and almost twice lighter than water. Lithium is soft and ductile. Lithium compounds color the flame in a beautiful carmine red color. This very sensitive method is used in qualitative analysis for the detection of lithium.

The configuration of the outer electron layer of the lithium atom is 2s1 (s-element). In compounds, it exhibits an oxidation state of +1.

Lithium is the first in the electrochemical series of voltages and displaces hydrogen not only from acids, but also from water. However, many chemical reactions in lithium are less vigorous than other alkali metals.

Lithium practically does not react with air components in the absence of moisture at room temperature. When heated in air above 200 ° C, the main product forms the oxide Li2O (only traces of Li2O2 peroxide are present). In humid air it gives predominantly Li3N nitride, with air humidity over 80% - LiOH hydroxide and Li2CO3 carbonate. Lithium nitride can also be obtained by heating a metal in a stream of nitrogen (lithium is one of the few elements that directly combine with nitrogen): 6Li + N2 = 2Li3N

Lithium easily fuses with almost all metals and is readily soluble in mercury. It combines directly with halogens (with iodine when heated). At 500 ° C, it reacts with hydrogen, forming hydride LiH, when interacting with water - hydroxide LiOH, with dilute acids - lithium salts, with ammonia - amide LiNH2, for example:

2Li + H2 = 2LiH

2Li + 2H2O = 2LiOH + H2

2Li + 2HF = 2LiF + H2

2Li + 2NH3 = 2LiNH2 + H2

LiH hydride - colorless crystals; used in various fields of chemistry as a reducing agent. When interacting with water, it releases a large amount of hydrogen (from 1 kg of LiH, 2820 liters of H2 are obtained):

LiH + H2O = LiOH + H2

This makes it possible to use LiH as a source of hydrogen for filling balloons and rescue equipment (inflatable boats, belts, etc.), as well as a kind of "warehouse" for storing and transporting flammable hydrogen (while it is necessary to protect LiH from the slightest traces of moisture).

Mixed lithium hydrides are widely used in organic synthesis, for example, lithium aluminum hydride LiAlH4, a selective reducing agent. It is obtained by the interaction of LiН with aluminum chloride А1С1з

LiOH hydroxide is a strong base (alkali), its aqueous solutions destroy glass and porcelain; Nickel, silver and gold are resistant to it. LiOH is used as an additive to the electrolyte of alkaline batteries, which increases their service life by 2-3 times and their capacity by 20%. On the basis of LiOH and organic acids (especially stearic and palmitic acids), frost and heat-resistant greases (lithols) are produced to protect metals from corrosion in the temperature range from -40 to +130 "C.

Lithium hydroxide is also used as a carbon dioxide scavenger in gas masks, submarines, airplanes and spaceships.

Receiving and applying. The raw materials for producing lithium are its salts, which are extracted from minerals. Depending on the composition, minerals are decomposed with sulfuric acid H2SO4 (acid method) or sintering with calcium oxide CaO and its carbonate CaCO3 (alkaline method), with potassium sulfate K2SO4 (salt method), with calcium carbonate and its chloride CaCl (alkaline-salt method) ... With the acid method, a solution of Li2SO4 sulfate is obtained [the latter is freed from impurities by treatment with calcium hydroxide Ca (OH) 2 and soda Na2Co3]. The cake formed by other methods of decomposition of minerals is leached with water; in this case, with the alkaline method, LiOH passes into the solution, with the salt method - Li 2SO4, with the alkaline-salt method - LiCl. All these methods, except for alkaline, provide for the production of the finished product in the form of Li2CO3 carbonate. which is used directly or as a source for the synthesis of other lithium compounds.

Lithium metal is obtained by electrolysis of a molten mixture of LiCl and potassium chloride KCl or barium chloride BaCl2 with further purification from impurities.

The interest in lithium is enormous. This is primarily due to the fact that it is a source of industrial production of tritium (a heavy hydrogen nuclide), which is the main component of the hydrogen bomb and the main fuel for thermonuclear reactors. A thermonuclear reaction is carried out between the 6Li nuclide and neutrons (neutral particles with a mass number of 1); reaction products - tritium 3H and helium 4He:

63Li + 10n = 31 H + 42He

A large amount of lithium is used in metallurgy. Magnesium alloy with 10% lithium is stronger and lighter than magnesium itself. Alloys of aluminum and lithium - scleron and aeron, containing only 0.1% lithium, in addition to being light, have high strength, ductility, and increased resistance to corrosion; they are used in aviation. The addition of 0.04% lithium to lead-calcium bearing alloys increases their hardness and reduces the coefficient of friction.

Lithium halides and carbonate are used in the production of optical, acid-resistant and other special glasses, as well as heat-resistant porcelain and ceramics, various glazes and enamels.

Small lithium crumbs cause chemical burns to damp skin and eyes. Lithium salts irritate the skin. When working with lithium hydroxide, take the same precautions as when working with sodium and potassium hydroxides.





Sodium (from Arab, natrun, Greek. Nitrone -natural soda, chemical element of subgroup Ia of the periodic system; atomic number 11, atomic mass 22.98977; refers to alkali metals. In nature it occurs in the form of one stable nuclide 23 Na.

Even in ancient times, sodium compounds were known - table salt (sodium chloride) NaCl, caustic alkali (sodium hydroxide) NaOH and soda (sodium carbonate) Na2CO3. The last substance the ancient Greeks called "nitron"; hence the modern name of the metal - "sodium". However, in Great Britain, the USA, Italy, France, the word sodium is preserved (from the Spanish word "soda", which has the same meaning as in Russian).

For the first time about obtaining sodium (and potassium) was reported by the English chemist and physicist H. Davy at a meeting of the Royal Society in London in 1807. He was able to decompose caustic alkalis KOH and NaOH by the action of an electric current and isolate previously unknown metals with extraordinary properties. These metals very quickly oxidized in air, and floated on the surface of the water, releasing hydrogen from it.

Prevalence in nature. Sodium is one of the most abundant elements in nature. Its content in the earth's crust is 2.64% by weight. In the hydrosphere, it is contained in the form of soluble salts in an amount of about 2.9% (with a total salt concentration in seawater of 3.5-3.7%). The presence of sodium has been established in the atmosphere of the Sun and in interstellar space. in nature, sodium is found only in the form of salts. The most important minerals are halite (rock salt) NaCl, mirabilite (Glauber's salt) Na2SO4 * 10H2O, thenardite Na2SO4, Chelyan nitrate NaNO3, natural silicates such as albite Na, nepheline Na

Russia is extremely rich in rock salt deposits (for example, Solikamsk, Usolye-Sibirskoe, etc.), large deposits of the mineral trona in Siberia.

Properties. Sodium is a silvery-white low-melting metal, m.p. 97.86 ° C, bp. 883.15 ° C. It is one of the lightest metals - it is lighter than water (density 0.99 g / cm3 at 19.7 ° C). Sodium and its compounds color the burner flame yellow. This reaction is so sensitive that it reveals the slightest trace of sodium everywhere (for example, in room or street dust).

Sodium is one of the most active elements in the periodic table. The outer electron layer of the sodium atom contains one electron (configuration 3s1, sodium - s-element). Sodium easily gives up its only valence electron and therefore always exhibits an oxidation state of +1 in its compounds.

In air, sodium is actively oxidized, forming, depending on the conditions, the oxide Na2O or peroxide Na2O2. Therefore, sodium is stored under a layer of kerosene or mineral oil. Reacts vigorously with water, displacing hydrogen:

2Na + H20 = 2NaOH + H2

Such a reaction occurs even with ice at a temperature of -80 ° C, and with warm water or at the contact surface it goes with an explosion (it’s not for nothing that they say: “If you don’t want to become a freak, don’t throw sodium into the water”).

Sodium reacts directly with all non-metals: at 200 ° C it begins to absorb hydrogen, forming a very hygroscopic hydride NaH; with nitrogen in an electric discharge gives the nitride Na3N or azide NaN3; ignites in a fluorine atmosphere; in chlorine burns at a temperature; reacts with bromine only when heated:

2Na + H2 = 2NaH

6Na + N2 = 2Na3N or 2Na + 3Na2 = 2NaN3

2Na + С12 = 2NaСl




At 800-900 ° C, sodium combines with carbon to form the carbide Na2C2; when rubbed with sulfur gives Na2S sulfide and a mixture of polysulfides (Na2S3 and Na2S4)

Sodium readily dissolves in liquid ammonia, the resulting blue solution has a metallic conductivity, with gaseous ammonia at 300-400 "C or in the presence of a catalyst when cooled to -30 C gives the amide NaNH2.

Sodium forms compounds with other metals (intermetallic compounds), for example, with silver, gold, cadmium, lead, potassium and some others. With mercury, it gives amalgams NaHg2, NaHg4, etc. The most important are liquid amalgams, which are formed with the gradual introduction of sodium into mercury, which is under a layer of kerosene or mineral oil.

Sodium forms salts with dilute acids.

Receiving and applying. The main method for producing sodium is electrolysis of molten table salt. In this case, chlorine is released at the anode, and sodium at the cathode. To reduce the melting point of the electrolyte, other salts are added to table salt: KCl, NaF, CaCl2. Electrolysis is carried out in electrolysers with a diaphragm; anodes are made of graphite, cathodes are made of copper or iron.

Sodium can be obtained by electrolysis of NaOH hydroxide melt, and small amounts can be obtained by decomposition of NaN3 azide.

Metallic sodium is used to reduce pure metals from their compounds - potassium (from KOH), titanium (from TiCl4), etc. Sodium-potassium alloy is a coolant for nuclear reactors, since alkali metals poorly absorb neutrons and therefore do not interfere with the fission of uranium nuclei. Sodium vapor, which has a bright yellow glow, is used to fill gas-discharge lamps used to illuminate highways, marinas, train stations, etc. Sodium is used in medicine: the artificially obtained nuclide 24Na is used for the radiological treatment of certain forms of leukemia and for diagnostic purposes.

The use of sodium compounds is much more extensive.

Na2O2 peroxide - colorless crystals, yellow technical product. When heated to 311-400 ° C, it begins to release oxygen, and at 540 ° C it rapidly decomposes. Strong oxidizing agent, which makes it suitable for bleaching fabrics and other materials. It absorbs CO2 in the air ”, releasing oxygen and forming carbonate 2Na2O2 + 2CO2 = 2Na2Co3 + O2). This property is based on the use of Na2O2 for air regeneration in enclosed spaces and breathing apparatus of an insulating type (submarines, insulating gas masks, etc.).

NaOH hydroxide; outdated name - caustic soda, technical name - caustic soda (from Latin caustic - caustic, burning); one of the strongest foundations. The technical product, in addition to NaOH, contains impurities (up to 3% Na2CO3 and up to 1.5% NaCl). A large amount of NaOH is used for the preparation of electrolytes for alkaline batteries, for the production of paper, soap, paints, cellulose, and is used for refining petroleum and oils.

Of sodium salts, chromate Na2CrO4 is used - in the production of dyes, as a mordant for dyeing fabrics and a tanning agent in the tanning industry; sulfite Na2SO3 -component of fixers and developers in photography; hydrosulfite NaHSO3 - bleach of fabrics, natural fibers, used for canning fruits, vegetables and vegetable feed; thiosulfate Na2S2O3 - to remove chlorine during fabric bleaching, as a fixative in photography, an antidote for poisoning with compounds of mercury, arsenic, etc., anti-inflammatory agent; chlorate NaClO3 - oxidizing agent in various pyrotechnic compositions; triphosphate Na5P3O10 -additive to synthetic detergents for water softening.

Sodium, NaOH and its solutions cause severe burns to the skin and mucous membranes.





In appearance and properties, potassium is similar to sodium, but more reactive. Reacts vigorously with water and ignites hydrogen. Burns in air, forming orange superoxide KO2. At room temperature, it reacts with halogens, with moderate heating - with hydrogen, sulfur. In humid air, it quickly becomes covered with a KOH layer. Store potassium under a layer of gasoline or kerosene.

The greatest practical application is found for potassium compounds - KOH hydroxide, KNO3 nitrate and K2CO3 carbonate.

Potassium hydroxide KOH (technical name - caustic potassium) - white crystals that spread in humid air and absorb carbon dioxide (K2CO3 and KHCO3 are formed). It dissolves very well in water with a high exo-effect. The aqueous solution is highly alkaline.

Potassium hydroxide is produced by electrolysis of a KCl solution (similar to the production of NaOH). The starting potassium chloride KCl is obtained from natural raw materials (minerals sylvin KCl and carnallite KMgC13 6H20). KOH is used for the synthesis of various potassium salts, liquid soap, dyes, as an electrolyte in batteries.

Potassium nitrate KNO3 (potassium nitrate mineral) - white crystals, very bitter in taste, low melting point (melting point = 339 ° С). Let's well dissolve in water (no hydrolysis). When heated above the melting point, it decomposes into potassium nitrite KNO2 and oxygen O2, exhibits strong oxidizing properties. Sulfur and charcoal ignite upon contact with the KNO3 melt, and the C + S mixture explodes (combustion of "black powder"):

2КNO3 + ЗС (coal) + S = N2 + 3CO2 + K2S

Potassium nitrate is used in the production of glass and mineral fertilizers.

Potassium carbonate K2CO3 (technical name - potash) is a white hygroscopic powder. It dissolves very well in water, strongly hydrolyzes by anion and creates an alkaline environment in solution. Used in the manufacture of glass and soap.

Obtaining K2CO3 is based on the reactions:

K2SO4 + Ca (OH) 2 + 2CO = 2K (HCOO) + CaSO4

2K (НСОО) + O2 = К2С03 + Н20 + С02

Potassium sulfate from natural raw materials (minerals KMg (SO4) Cl 3H20 kainite and K2Mg (SO4) 2 * 6H20 shonite) are heated with Ca (OH) 2 slaked lime in a CO atmosphere (under a pressure of 15 atm) to obtain potassium formate K (HCOO) , which is calcined in a stream of air.

Potassium is a vital element for plants and animals. Potash fertilizers are potassium salts, both natural and products of their processing (KCl, K2SO4, KNO3); high content of potassium salts in plant ash.

Potassium is the ninth most abundant element in the earth's crust. It is contained only in bound form in minerals, sea water (up to 0.38 g of K + ions in 1 liter), plants and living organisms (inside cells). The human body has = 175 g of potassium, the daily requirement reaches ~ 4 g. The radioactive isotope 40K (an impurity to the predominant stable isotope 39K) decays very slowly (half-life 1 109 years), it, along with the isotopes 238U and 232Тh, makes a large contribution to

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Metals in the periodic table. The structure of metal atoms. General characteristics of metals.

Position of metals in the periodic table If we draw a diagonal from boron to astatine in the table of D.I. Elements located near the diagonal have dual properties: in some of their compounds they behave like metals; in some - as non-metals. The structure of metal atoms In periods and main subgroups, there are regularities in the change in metallic properties. The atoms of many metals have 1, 2 or 3 valence electrons, for example:

Na (+ 11): 1S 2 2S 2 2p 6 3S 1

Ca (+ 20): 1S 2 2S 2 2p 6 3S 2 3p 6 3d 0 4S 2

Alkali metals (group 1, main subgroup): ... nS 1. Alkaline earth metals (group 2, main subgroup): ... nS 2. The properties of metal atoms are periodically dependent on their location in the table of D.I. Mendeleev. IN THE MAIN SUBGROUP:

does not change.

Atom radius increases

Electronegativity decreases.

Restorative properties intensify.

Metallic properties intensify.

IN THE PERIOD:
Nuclear charges of atoms increase.

Radii of atoms decrease.

The number of electrons in the outer layer increases.

Electronegativity increases.

Restorative properties decrease.

Metallic properties weaken.

Metal crystal structure Most solids exist in crystalline form: their particles are arranged in a strict order, forming a regular spatial structure - a crystal lattice. A crystal is a solid, whose particles (atoms, molecules, ions) are arranged in a certain, periodically repeating order (in nodes). When mentally connecting nodes with lines, a spatial framework is formed - a crystal lattice. Crystal structures of metals in the form of spherical packings



a - copper; b - magnesium; c - α-modification of iron

Metal atoms tend to donate their outer electrons. In a piece of metal, ingot or metal product, the metal atoms give up external electrons and send them to this piece, ingot or product, thus turning into ions. The "torn off" electrons move from one ion to another, temporarily reunite with them into atoms, torn off again, and this process occurs continuously. Metals have a crystal lattice, in the nodes of which there are atoms or ions (+); between them are free electrons (electron gas). The communication scheme in metal can be displayed as follows:

M 0 ↔ nē + M n +,

atom - ion

where n Is the number of external electrons participating in the bond (y Na - 1 ē, at Ca - 2 ē, at Al - 3 ē This type of bond is observed in metals - simple substances-metals and in alloys. A metal bond is a bond between positively charged metal ions and free electrons in the crystal lattice of metals. The metal bond has some similarity with the covalent, but also some difference, since the metal the connection is based on the socialization of electrons (similarity), all atoms take part in the socialization of these electrons (difference). That is why crystals with a metallic bond are ductile, electrically conductive and have a metallic luster. However, in the vapor state, metal atoms are linked by a covalent bond, metal pairs are composed of individual molecules (monoatomic and diatomic). General characteristics of metals

The ability of atoms to donate electrons (oxidize)	← Increasing
Interaction with atmospheric oxygen	Oxidizes quickly at ambient temperatures	Oxidize slowly at normal temperature or when heated	Do not oxidize
Interaction with water	At normal temperatures, H 2 is released and hydroxide is formed	When heated, Н 2 is released	H 2 is not displaced from water
5interaction with acids	Displace H 2 from dilute acids	Does not displace H 2 from dilute acids
		React with conc. and decomp. HNO 3 and with conc. H 2 SO 4 when heated		Do not react with acids
Being in nature	Only in connections	In connections and in free form		Mostly loose
Methods of obtaining	Electrolysis of melts	Reduction with coal, carbon monoxide (2), alumothermy, or electrolysis of aqueous solutions of salts
The ability of ions to attach electrons (recover)	Li K Ca Na Mg Al Mn Zn Cr Fe Ni Sn Pb (H) Cu Hg Ag Pt Au
	Increasing →

Electrochemical series of metal voltages. Physical and chemical properties of metals

General physical properties of metals The general physical properties of metals are determined by the metallic bond and the metallic crystal lattice. Malleability, ductility Mechanical action on a metal crystal causes a displacement of the layers of atoms. Since the electrons in the metal move throughout the crystal, no breaking of bonds occurs. Plasticity decreases in a row Au, Ag, Cu, Sn, Pb, Zn, Fe... Gold, for example, can be rolled into sheets no more than 0.001 mm thick, which are used for gilding various items. Aluminum foil appeared relatively recently and earlier tea, chocolate was forged into tin foil, which was called stanyol. However, Mn and Bi do not have ductility: these are brittle metals. Metallic luster Metallic luster, which in the powder is lost by all metals, except Al and Mg... The brightest metals are Hg(the famous "Venetian mirrors" were made from it in the Middle Ages), Ag(now modern mirrors are made from it with the help of the reaction of the "silver mirror"). By color (conventionally), ferrous and non-ferrous metals are distinguished. Among the latter, we will single out precious ones - Au, Ag, Pt. Gold is the metal of jewelers. It was on its basis that wonderful Faberge Easter eggs were made. Ringing Metals ring, and this property is used to make bells (remember the Tsar Bell in the Moscow Kremlin). The most sonorous metals are Au, Ag, Ci. Copper rings with a thick, humming ring - a crimson ring. This is a figurative expression not in honor of the raspberry berry, but in honor of the Dutch city of Malina, where the first church bells were melted. Later in Russia, Russian craftsmen began to cast bells of even better quality, and residents of cities and towns donated gold and silver jewelry so that the bell cast for churches would sound better. In some Russian pawnshops, the authenticity of gold rings accepted for commission was determined by the ringing of a gold wedding ring suspended from a woman's hair (a very long and clear high-pitched sound is heard). Under normal conditions, all metals except mercury Hg are solids. The hardest metal is chromium Cr, which scratches glass. The softest are alkali metals, they are cut with a knife. Alkali metals are stored with great precautions - Na - in kerosene, and Li - in petroleum jelly because of its lightness, kerosene - in a glass jar, a jar - in asbestos chips, asbestos - in a tin can. Electrical conductivity The good electrical conductivity of metals is explained by the presence of free electrons in them, which, under the influence of even a small potential difference, acquire a directional movement from the negative to the positive pole. As the temperature rises, the vibrations of atoms (ions) intensify, which makes it difficult for the directional movement of electrons and thereby leads to a decrease in electrical conductivity. At low temperatures, the vibrational motion, on the contrary, greatly decreases and the electrical conductivity increases sharply. Metals exhibit superconductivity near absolute zero. Ag, Cu, Au, Al, Fe have the highest electrical conductivity; worst conductors - Hg, Pb, W. Thermal conductivity Under normal conditions, the thermal conductivity of metals changes in basically the same sequence as their electrical conductivity. Thermal conductivity is due to the high mobility of free electrons and the vibrational motion of atoms, due to which there is a rapid equalization of temperature in the mass of the metal. The highest thermal conductivity is in silver and copper, the lowest is in bismuth and mercury. Density The density of metals is different. It is the less, the less the atomic mass of the metal element and the larger the radius of its atom. The lightest metal is lithium (density 0.53 g / cm 3), the heaviest is osmium (density 22.6 g / cm 3). Metals with a density of less than 5 g / cm 3 are called light, the rest are heavy. The melting and boiling points of metals are varied. The most low-melting metal - mercury (bale = -38.9 ° C), cesium and gallium - melt at 29 and 29.8 ° C, respectively. Tungsten is the most refractory metal (bale t = 3390 ° C). The concept of allotropy of metals on the example of tin Some metals have allotropic modifications. For example, tin is distinguished into:
α-tin, or gray tin ("tin plague" - the transformation of ordinary β-tin into α-tin at low temperatures caused the death of R. Scott's expedition to the South Pole, who lost all fuel, since it was stored in tanks sealed with tin ), is stable for t<14°С, серый порошок. β-олово, или белое олово (t = 14 ― 161°С) очень мягкий металл, но тверже свинца, поддается литью и пайке. Используется в сплавах, например, для изготовления белой жести (луженого железа).
Electrochemical series of voltages of metals and its two rules The arrangement of atoms in a row according to their reactivity can be represented as follows: Li, K, Ca, Na, Mg, Al, Mn, Zn, Fe, Ni, Sn, Pb,N 2 , Сu, Hg, Ag, Pt, Au... The position of an element in the electrochemical series shows how easily it forms ions in an aqueous solution, i.e., its reactivity. The reactivity of elements depends on the ability to accept or donate electrons involved in the formation of a bond. 1st rule of a series of voltages If the metal is in this row before hydrogen, it is able to displace it from acid solutions, if after hydrogen, then not. For instance, Zn, Mg, Al gave a substitution reaction with acids (they are in the series of voltages up to H), a Cu no (she after H). 2nd rule of a series of voltages If the metal is in the series of stresses up to the metal of the salt, then it is able to displace this metal from the solution of its salt. For example, CuSO 4 + Fe = FeSO 4 + Cu. In such cases, the position of the metal before or after hydrogen may not matter, it is important that the reacting metal precedes the metal forming the salt: Cu + 2AgNO 3 = 2Ag + Cu (NO 3) 2. General chemical properties of metals In chemical reactions, metals are reducing agents (they donate electrons). Interaction with simple substances.
With halogens, metals form salts - halides:
Mg + Cl 2 = MgCl 2; Zn + Br 2 = ZnBr 2.
Metals form oxides with oxygen:
4Na + O 2 = 2 Na 2 O; 2Cu + O 2 = 2CuO.
With sulfur, metals form salts - sulfides:
Fe + S = FeS.
With hydrogen, the most active metals form hydrides, for example:
Ca + H 2 = CaH 2.
with carbon, many metals form carbides:
Ca + 2C = CaC 2. Interaction with complex substances
Metals at the beginning of a series of voltages (from lithium to sodium), under normal conditions, displace hydrogen from water and form alkalis, for example:
2Na + 2H 2 O = 2NaOH + H 2.
Metals located in a series of voltages up to hydrogen interact with dilute acids (НCl, Н 2 SO 4, etc.), as a result of which salts are formed and hydrogen is released, for example:
2Al + 6НCl = 2AlCl 3 + 3H 2.
Metals interact with solutions of salts of less active metals, as a result of which a salt of a more active metal is formed, and less active metal is released in a free form, for example:
CuSO 4 + Fe = FeSO 4 + Cu.

Metals in nature.

Finding metals in nature. Most metals are found in nature in the form of various compounds: active metals are found only in the form of compounds; low-activity metals - in the form of compounds and in free form; noble metals (Ag, Pt, Au ...) in free form. Native metals are usually contained in small quantities in the form of grains or inclusions in rocks. Rarely, there are also quite large pieces of metal - nuggets. Many metals in nature exist in a bound state in the form of chemical natural compounds - minerals... Very often these are oxides, for example, iron minerals: red iron ore Fe 2 O 3, brown iron ore 2Fe 2 O 3 ∙ 3H 2 O, magnetic iron ore Fe 3 O 4. Minerals are part of rocks and ores. Ores are called natural formations containing minerals, in which metals are in quantities technologically and economically suitable for the production of metals in industry. By the chemical composition of the mineral included in the ore, oxide, sulfide and other ores are distinguished. Usually, before obtaining metals from ore, it is preliminarily enrich - separate waste rock, impurities, as a result, a concentrate is formed, which serves as a raw material for metallurgical production. Methods for obtaining metals. The production of metals from their compounds is the task of metallurgy. Any metallurgical process is a process of reduction of metal ions with the help of various reducing agents, as a result of which metals are obtained in a free form. Depending on the method of carrying out the metallurgical process, pyrometallurgy, hydrometallurgy and electrometallurgy are distinguished. Pyrometallurgy Is the production of metals from their compounds at high temperatures using various reducing agents: carbon, carbon monoxide (II), hydrogen, metals (aluminum, magnesium), etc. Examples of metal reduction
coal:
ZnO + C → Zn + CO 2;
carbon monoxide:
Fe 2 O 3 + 3CO → 2Fe + 3CO 2;
hydrogen:
WO 3 + 3H 2 → W + 3H 2 O; CoO + H 2 → Co + H 2 O;
aluminum (alumothermy):
4Al + 3MnO 2 → 2Al 2 O 3 + 3Mn; Cr 2 O 3 + 2Al = 2Al 2 O 3 + 2Cr;
magnesium:
TiCl 4 + 2Mg = Ti + 2MgCl 2. Hydrometallurgy- This is the production of metals, which consists of two processes: 1) the natural compound of the metal dissolves in acid, resulting in a solution of the metal salt; 2) from the resulting solution, this metal is displaced by a more active metal. For instance:
2CuS + 3O 2 = 2CuO + 2SO 2.
CuO + H 2 SO 4 = CuSO 4 + H 2 O.
CuSO 4 + Fe = FeSO 4 + Cu.
Electrometallurgy- This is the production of metals by electrolysis of solutions or melts of their compounds. Electric current plays the role of a reducing agent in the electrolysis process.

General characteristics of the metals of the IA group.

The metals of the main subgroup of the first group (IA-group) include lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), francium (Fr). These metals are called alkali metals because they and their oxides form alkalis when interacting with water. Alkali metals are s-elements. On the outer electron layer, metal atoms have one s-electron (ns 1). Potassium, sodium - simple substances



Alkali metals in ampoules:
a - cesium; b - rubidium; c - potassium; g - sodium Basic information about the elements of the IA group

Element	Li lithium	Na sodium	K potassium	Rb rubidium	Cs cesium	Fr france
Atomic number	3	11	19	37	55	87
The structure of the outer electron shells of atoms	ns 1 np 0, where n = 2, 3, 4, 5, 6, 7, n is the number of the period
Oxidation state	+1	+1	+1	+1	+1	+1
Basic natural compounds	Li 2 O · Al 2 O 3 · 4SiO 2 (spodumene); LiAl (PO 4) F, LiAl (PO 4) OH (amblygonite)	NaCl (table salt); Na 2 SO 4 · 10H 2 O (Glauber's salt, mirabilit); КCl NaCl (sylvite)	KCl (sylvinite), KCl NaCl (sylvinite); K (potassium feldspar, orthogonal); KCl MgCl 2 6H 2 O (carnallite) - found in plants	As an isoamorphic impurity in potassium minerals - sylvinite and carnallite	4Cs 2 O · 4Al 2 O 3 · 18 SiO 2 · 2H 2 O (semi-cyt); companion of potassium minerals	Α-decay product of actinium

Physical properties Potassium and sodium are soft silvery metals (cut with a knife); ρ (K) = 860 kg / m 3, Tm (K) = 63.7 ° C, ρ (Na) = 970 kg / m 3, Tm (Na) = 97.8 ° C. They have high thermal and electrical conductivity, paint the flame in characteristic colors: K - in a pale violet color, Na - in yellow.