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Presentation on the topic: Alkali metals grade 9

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ALKALINE METALS Alkali metals are elements of the main subgroup I of group I of Mendeleev's Periodic Table of Chemical Elements: lithium Li, sodium Na, potassium K, rubidium Rb, cesium Cs and francium Fr. These metals are called alkali metals because most of their compounds are soluble in water. In Slavic, "leach" means "dissolve", which is what determined the name of this group of metals. When alkali metals are dissolved in water, soluble hydroxides called alkalis are formed.

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general characteristics alkali metals In the Periodic Table, they follow immediately after inert gases, therefore, the peculiarity of the structure of atoms of alkali metals is that they contain one electron at the external energy level: their electronic configuration ns1. It is obvious that the valence electrons of alkali metals can be easily removed, because it is energetically favorable for the atom to donate an electron and acquire the configuration of an inert gas. Therefore, all alkali metals are characterized by reducing properties. This is confirmed by the low values ​​of their ionization potentials (the ionization potential of the cesium atom is one of the lowest) and electronegativity (EO).

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Chemical properties of alkali metals Due to the high chemical activity of alkali metals in relation to water, oxygen, and sometimes even nitrogen (Li, Cs), they are stored under a layer of kerosene. To carry out a reaction with an alkali metal, a piece of the required size is carefully cut with a scalpel under a layer of kerosene, in an argon atmosphere, the surface of the metal is thoroughly cleaned from the products of its interaction with air, and only then the sample is placed in a reaction vessel. 1. Interaction with water. An important property of alkali metals is their high activity towards water. Lithium reacts most calmly (without explosion) with water. When carrying out a similar reaction, sodium burns with a yellow flame and a small explosion occurs. Potassium is even more active: in this case, the explosion is much stronger, and the flame is colored purple.

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2. Interaction with oxygen. The combustion products of alkali metals in air have a different composition depending on the activity of the metal. Only lithium burns in air with the formation of a stoichiometric oxide: When sodium burns, Na2O2 peroxide is mainly formed with a small admixture of NaO2 superoxide: The combustion products of potassium, rubidium and cesium contain mainly superoxides:

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To obtain sodium and potassium oxides, mixtures of hydroxide, peroxide or superoxide with an excess of metal in the absence of oxygen are heated: For oxygen compounds of alkali metals, the following regularity is characteristic: as the radius of the alkali metal cation increases, the stability of oxygen compounds containing the peroxide ion О22− and superoxide O2 - ion. Heavy alkali metals are characterized by the formation of fairly stable ozonides of the composition EO3. All oxygen compounds have different colors, the intensity of which deepens in the range from Li to Cs:

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Alkali metal oxides have all the properties inherent in basic oxides: they react with water, acid oxides and acids: Peroxides and superoxides exhibit the properties of strong oxidizing agents: Peroxides and superoxides interact intensively with water, forming hydroxides:

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3. Interaction with other substances. Alkali metals react with many non-metals. When heated, they combine with hydrogen to form hydrides, with halogens, sulfur, nitrogen, phosphorus, carbon and silicon to form, respectively, halides, sulfides, nitrides, phosphides, carbides and silicides: When heated, alkali metals can react with other metals, forming intermetallic compounds. Alkali metals react actively (explosively) with acids. Alkali metals dissolve in liquid ammonia and its derivatives - amines and amides: When dissolved in liquid ammonia, an alkali metal loses an electron, which is solvated by ammonia molecules and gives the solution a blue color. The formed amides are readily decomposed by water with the formation of alkali and ammonia:

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Lithium Most light metal, has two stable isotopes with atomic masses 6 and 7; the more common heavy isotope, its content is 92.6% of all lithium atoms. Lithium was discovered by A. Arfvedson in 1817 and isolated by R. Bunsen and A. Matisen in 1855. It is used in the manufacture of thermonuclear weapons (hydrogen bomb), to increase the hardness of alloys, and in pharmaceuticals. Lithium salts are used to increase the hardness and chemical resistance glass, in alkaline battery technology, for binding oxygen during welding.

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Potassium Known since antiquity, it was also isolated by H. Davy in 1807. Potassium salts are well known: potassium nitrate (potassium nitrate KNO3), potash (potassium carbonate K2CO3), caustic potassium (potassium hydroxide KOH), etc. Metallic potassium is also found various applications in the technology of heat transfer alloys.

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Rubidium Rubidium was discovered by spectroscopy by R. Bunsen in 1861; contains 27.85% of radioactive rubidium Rb-87. Rubidium, like other metals of subgroup IA, is chemically highly reactive and must be stored under a layer of oil or kerosene to avoid oxidation with atmospheric oxygen. Rubidium finds a variety of uses, including solar cell technology, radio vacuum devices, and pharmaceuticals.

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Performed by Shlyakhovoy Vladimir Frantsiy The last member of the family of alkali metals francium is so radioactive that it is not present in the earth's crust in more than trace amounts. Information about france and its compounds is based on the study of its negligible amount, artificially obtained (on a high-energy accelerator) during the a-decay of actinium-227. The longest-lived isotope 22387Fr decays in 21 min into 22388Ra and b-particles. According to a rough estimate, the metallic radius of francium is 2.7. Francium possesses most of the properties characteristic of other alkali metals and has a high electron-donating activity. It forms soluble salts and hydroxide. In all compounds, francium exhibits oxidation state I.

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Municipal budgetary educational institution "Boarding school No. 1 secondary (full) general education»Of the urban district, the city of Sterlitamak, Republic of Bashkortostan Completed by the chemistry teacher of the first qualification category Safikanov Akhat Faizrakhmanovich Safikanov AF.

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Mendeleev's periodic table of chemical elements Groups of elements I III II VIII IV V VI VII II I III VII VI V IV 2 1 3 4 5 6 7 10 F fluorine 9 18.9984 Br Bromine 35 79.904 I Iodine 53 126.904 Cl Chlorine 17 35.453 At Astatine 85 210 9 8 Alkali metals Safikanov A.F.

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Groups of elements I III II VIII IV V VI VII II I III VII VI V IV 2 1 3 4 5 6 7 10 9 8 Alkali metals Periodic table of chemical elements of D. I. Mendeleev In the main subgroup: The number of electrons on the outer layer does not change Radius atom increases Electronegativity decreases Reducing properties increase Metallic properties increase Safikanov A.F.

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Periodic table of chemical elements of D.I. Mendeleev Groups of elements I III II VIII IV V VI VII II I III VII VI V IV 2 1 3 4 5 6 7 9 8 10 Lithium (Li) Appearance simple substance Soft metal, silvery-white. Electronic coefficient 2s1 EO (according to Pauling) 0.98 Oxidation state 1 Density 0.534 g / cm³ Melting point 453.69 K Boiling point 1613 K Safikanov A.F.

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Periodic table of chemical elements of D. I. Mendeleev Groups of elements I III II VIII IV V VI VII II I III VII VI V IV 2 1 3 4 5 6 7 9 8 10 Sodium / Natrium (Na) Appearance of a simple substance silvery-white soft metal Electronic kofigurance 3s1 EO (according to Pauling) 0.93 Oxidation state 1 Density 0.971 g / cm ³ Melting point 370.96 K Boiling point 1156.1 K Safikanov A.F.

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Periodic table of chemical elements of D. I. Mendeleev Groups of elements I III II VIII IV V VI VII II I III VII VI V IV 2 1 3 4 5 6 7 9 8 10 Potassium / Kalium (K) Appearance of a simple substance Silver-white soft metal Electronic configuration 3d10 4s1 EO (according to Pauling) 0.82 Oxidation state 1 Density 0.856 g / cm³ Melting point 336.8 K Boiling point 1047 K Safikanov A.F.

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Periodic table of chemical elements of D. I. Mendeleev Groups of elements I III II VIII IV V VI VII II I III VII VI V IV 2 1 3 4 5 6 7 9 8 10 Rubidium / Rubidium (Rb) Appearance of a simple substance Silver-white soft metal Electronic configuration 5s1 EO (according to Pauling) 0.82 Oxidation state 1 Density 1.532 g / cm³ Melting point 312.2 K Boiling point 961 K Safikanov A.F.

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Periodic table of chemical elements of D. I. Mendeleev Groups of elements I III II VIII IV V VI VII II I III VII VI V IV 2 1 3 4 5 6 7 9 8 10 Cesium / Cesium (Cs) The appearance of a simple substance is very soft viscous silvery -yellow gold-like metal Electronic configuration 6s1 EO (according to Pauling) 0.79 Oxidation state 1 Density 1.873 g / cm Melting point 301.6 K Boiling point 951.6 K Safikanov A.F.

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Periodic table of chemical elements of D. I. Mendeleev Groups of elements I III II VIII IV V VI VII II I III VII VI V IV 2 1 3 4 5 6 7 9 8 10 Francium (Fr) Appearance of a simple substance radioactive alkali metal Electronic configuration 7s1 EO (according to Pauling) 2.2 Oxidation state 1 Density 1.87 g / cm Melting point 300 K Boiling point 950 K Safikanov A.F.

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Alkali metals Lithium Sodium Potassium Rubidium Cesium Friction History of discovery Safikanov A.F.

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Lithium was discovered in 1817 by A. Arfvedson in the mineral petalite. Berzelius suggested calling it Lithion, since this alkali was first found in the "kingdom of minerals" (stones); this name is derived from the Greek - stone. Metallic lithium was first obtained in 1818 by G. Davy by electrolysis of alkali. In 1855 Bunsen and Mattessen developed an industrial method for producing metallic lithium by electrolysis of lithium chloride. Arfvedson Johan August (12.01.1792 - 28.10.1841) History of the discovery of lithium Safikanov A.F.

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Sodium (Natrium, from English and French Sodium, German Natrium from Hebrew neter is a bubbling substance. In 1807, H. Davy, by electrolysis of slightly moistened solid alkalis, obtained a free metal - sodium, calling it Sodium. next year Hilbert suggested calling the new metal Natronium; Berzelius abbreviated the latter name to "sodium" (Natrium). Humphry Davy (12/17/1778 - 05/29/1829) History of the discovery of sodium Safikanov A.F.

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Potassium (English Potassium, French Potassium, German Kalium) was discovered in 1807 by G. Davy, who produced the electrolysis of solid, slightly moistened caustic potassium. Davy called the new metal Potassium, but this name did not catch on. The godfather of the metal turned out to be Gilbert, the famous publisher of the Annalen der Physik magazine, who proposed the name "potassium"; it was adopted in Germany and Russia. The history of the discovery of potassium Humphry Davy (12/17/1778 - 05/29/1829) Safikanov A.F.

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Spectroscopic analysis of the mineral lepidolite (lithium and aluminum fluorosilicate) revealed two new red lines in the red part of the spectrum. R. Bunsen and G. Kirchhoff correctly assigned these lines to the new metal, which was named rubidium (Latin rubidus - red) because of the color of its spectral lines. Bunsen succeeded in obtaining rubidium in the form of a metal in 1863. The history of rubidium discovery Robert Wilhelm Bunsen (31.03.1811 - 16.08.1899) Gustav Robert Kirchhoff (12.03.1824 - 17.10.1887) Safikanov A.F.

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Cesium (English Cesium, French Cesium, German Cesium) is the first element discovered with spectral analysis... R. Bunsen and G. Kirchhoff found the spectral lines of the new element: one faintly blue and the other bright blue in the violet part of the spectrum. R. Bunsen called again exposed metal cesium (Casium) from lat. caesius - blue, light gray in ancient times, this word meant the blue of the clear sky. Pure metallic cesium was obtained electrolytically in 1882. History of the discovery of cesium Robert Wilhelm Bunsen (31.03.1811 - 16.08.1899) Gustav Robert Kirchhoff (12.03.1824 - 17.10.1887) Safikanov A.F.

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This element was predicted by D. I. Mendeleev (as Eka-cesium), and was discovered (by its radioactivity) in 1939 by Marguerite Pere, an employee of the Radium Institute in Paris with the serial number Z = 87 and a half-life of 21 minutes. She also gave him the name in 1964 in honor of her homeland - France. ... Microscopic amounts of France-223 and France-224 can be chemically isolated from the minerals uranium and thorium. Other isotopes of france are produced artificially using nuclear reactions. PERE (Perey) Margarita (19.10.1909 - 13.05.1975) History of the discovery of France A.F.Safikanov

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Spodumenn Photo Description of the mineral Chemical composition LiAl Color Colorless, red, yellow, green Density 3.1-3.2 g / cm3 Hardness 6.5 Safikanov A.F.

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Halite Photo Description of the mineral Chemical composition NaCl Color Colorless, red, yellow, blue Density 2.2-2.3 g / cm3 Hardness 2.5 Taste Salty AF Safikanov

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Sylvin Photo Description of the mineral Chemical composition KCl Color Colorless, milky white, dark red, pink Density 1.97-1.99 g / cm3 Hardness 1.5 Taste Corrosive AF Safikanov

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Carnalite Photo Description of the mineral Chemical composition MgCl2 · KCl · 6H2O Color Red, yellow, white, colorless Density 1.6 g / cm3 Hardness 1.5 Taste Hot salty Safikanov A.F.

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Chemical properties 2Na + Cl2 = 2NaCl (alkaline Me in an atmosphere of F2 and Cl2 ignites spontaneously) 4Li + O2 = 2Li2O 2Na + O2 = Na2O2 2K + 2O2 = K2O4 Li oxide Na peroxide Superoxide K 3) 2Na + H2 = 2NaH (when heated 200- 400oC) 4) 6Li + N2 = 2Li3N (Li - at room temperature, other alkaline Me - when heated) 5) 2Na + 2Н2О = 2NaОН + Н2 (Li - calmly, Na - vigorously, the rest - with an explosion - the released Н2 Rb ignites and Cs react not only with liquid Н2О, but also with ice. 6) 2Na + Н2SO4 = Na2SO4 + Н2 (proceeding very violently) 7) 2C2H5OH + 2Na = 2C2H5ONa + Н2 Alkali metals with water Safikanov A.F.

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Qualitative definition alkali metals Li + Na + K + To recognize alkali metal compounds by the color of the flame, the substance under investigation is introduced into the flame of the burner at the tip of an iron wire. Li + - carmine-red K + - violet Cs + - violet-blue Na + - yellow Rb + - red Safikanov A.F.

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1) Electrolysis of melts of alkali metal compounds: 2МеCl = 2Ме + Cl2 4МеOH = 4Ме + 2Н2О + О2 2) Reduction of oxides and hydroxides of alkali metals: 2Li2O + Si = 4Li + SiO2 KOH + Na = NaOH + K Obtaining alkali metals Bath consists of steel a shell with a fireclay lining, a graphite anode A and an annular iron cathode K, between which a mesh diaphragm is located. The electrolyte is a more low-melting mixture of it with 25% NaF and 12% KCl (which allows the process to be carried out at 610–650 ° C). Metallic sodium is collected in the upper part of the annular cathode space, from where it passes into the collection. As the electrolysis progresses, NaCl is added to the bath. Diagram of an electrolytic cell for sodium production Safikanov A.F.

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Application of alkali metals Lithium To obtain tritium Obtaining alloys for bearings Reducing agent in organic synthesis Chemical power sources Pyrotechnics AF Safikanov

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Topic: Compounds of alkali metals. Test on the topic: Alkali metals. Answers: 1 - d 2 - c 3 - b 4 - c 5 - a 6 - d 7 - b 8 - a 9 - b 10 - c. Evaluation scale: no errors - "5", 1.2 errors - "4", 3.4 errors - "3", more - "2" D / z § 11, exercise. 1 (b) p. 48. Alkali metals do not include: a) rubidium; c) potassium; b) cesium; d) copper. The electronic formula 1s2 2s2 2p6 3s2 3p6 4s1 corresponds to the element: a) lithium; c) potassium; b) sodium; d) copper. The atomic radius of the elements of group I of the main subgroup with an increase in the nuclear charge: a) changes periodically; c) does not change; b) increases; d) decreases. Alkali metals exhibit very strong: a) oxidizing properties; c) restorative properties; b) amphoteric properties; d) neutral properties. In all their compounds, alkali metals exhibit oxidation states: a) +1; c) +2; b) +3; d) +4. 6. The physical properties of alkali metals do not include: a) silvery-white; c) good electrical conductors; b) soft and light; d) refractory. 7. When the elements of the I group of the main subgroup interact with water, the following is formed: a) acid; c) oxide and hydrogen is evolved; b) alkali and hydrogen is released; d) salt. 8. When oxygen interacts with alkali metals, oxide is formed only with: a) lithium; c) potassium; b) sodium; d) rubidium. 9. Alkali metals do not interact with: a) non-metals; c) water; b) acid solutions; d) concentrated acids. 10. Sodium and potassium are stored in kerosene or mineral oil, because they: a) have a pungent odor; c) easily oxidized in air; b) very light; d) strong oxidants.

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2. Hydroxides of alkali metals a) physical properties: b) chemical properties: Instructions Pour sodium hydroxide into a clean test tube, add a few drops of phenolphthalein. What are you watching? Add hydrochloric acid solution to the same tube. What are you watching? Write down the reaction equation. Pour sodium hydroxide into a clean tube and add copper sulfate solution. What are you watching? Write down the reaction equation. Carefully add sodium hydroxide to the zinc hydroxide tube. What are you watching? Write down the reaction equation. Make a conclusion about the chemical properties of alkali metal hydroxides.

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2. Hydroxides of alkali metals c) application: Sodium hydroxide - NaOH - caustic soda, caustic soda, caustic. Potassium hydroxide - KOH - caustic potassium. NaOH and KOH - caustic alkalis, corrode fabrics and paper

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3. Salts of alkali metals baking soda potash table salt Glauber's salt crystalline soda Salt formula Name Application

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4. Significance of alkali metal compounds in the life of organisms Sodium and potassium ions play an important biological role: Na + is the main extracellular ion found in blood and lymph, and K + is the main intracellular ion. The ratio of the concentration of these ions regulates the blood pressure in a living organism and ensures the movement of salt solutions from the roots to the leaves of plants. Potassium ions - support the work of the heart muscle, help with rheumatism, improve bowel function. Potassium compounds - eliminate edema.

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An adult should consume 3.5 g of potassium ions with food per day. Task. 100g of dried apricots contains 2.034g of potassium. How many grams of dried apricots do you need to eat to get your daily potassium intake? Lesson summary: What physical and chemical properties are characteristic of oxides, hydroxides of alkali metals. Where are alkali metal hydroxides and salts used Thank you for your work.

Lithium (Latin - lithium), Li-chemical element of the first group, A-subgroup of the periodic system of D. I. Mendeleev, belongs to alkali metals, serial number 3, atomic mass is 6.939; under normal conditions, silvery white, light metal.

Natural lithium consists of two isotopes with mass numbers 6 and 7. An interesting detail: the cost of lithium isotopes is not at all proportional to their abundance. At the beginning of this decade, relatively pure lithium-7 in the United States cost almost 10 times the price of very high-purity lithium-6.

Two more lithium isotopes were obtained by artificial means. Their lifetimes are extremely short: lithium-8 has a half-life of 0.841 seconds, and lithium-9 has 0.168 seconds.

Lithium is a typical element of the earth's crust, a relatively rare element. (Content 3.2 × 10-3% by mass), it accumulates in the latest products of magma differentiation - pegmatites. There is little lithium in the mantle - in ultrabasic rocks only 5 × 10-3% (in basic rocks 1.5 × 10-3%, medium - 2 × 10-3%, acidic 4 × 10-3%). The proximity of the ionic radii of Li +, Fe2 + and Mg2 + allows lithium to enter the lattices of magnesian-ferrous silicates - pyroxenes and amphiboles. In granitoids, it is contained in the form of an isomorphic impurity in micas. Only in pegmatites and in the biosphere are known 28 independent lithium minerals (silicates, phosphates, etc.). They are all rare. In the biosphere, lithium migrates relatively weakly, its role in living matter is less than that of other alkali metals. It is easily extracted from the waters by clays; it is relatively scarce in the World Ocean (1.5 × 10-5%).

In the human body (weighing 70 kg) - 0.67 mg. lithium.

Potassium (Kalium)

Potassium is a chemical element of group I of the periodic system of Mendeleev; atomic number 19, atomic mass 39.098; silvery white, very light, soft and low-melting metal. The element consists of two stable isotopes - 39K (93.08%), 41K (6.91%) and one weakly radioactive 40K (0.01%) with a half-life of 1.32 × 109 years.

Being in nature

In nature, it is the ninth most abundant chemical element (the sixth among metals), it is found only in the form of compounds. It is part of many minerals, rocks, salt layers. The third most abundant metal in natural waters: 1 liter of seawater contains 0.38 g of K + ions. Potassium cations are well adsorbed by the soil and are hardly washed out by natural waters.

Vital important element for all organisms. K + ions are always found inside cells (unlike Na + ions). The human body contains about 175 g of potassium, the daily requirement is about 4 g. The lack of potassium in the soil is compensated by the introduction of potassium fertilizers - potassium chloride KCl, potassium sulfate K2SO4 and plant ash.

WHAT IS POTASSIUM CYANIDE NEEDED FOR?

Being in nature

Besides 223Fr, several isotopes of element # 87 are now known. But only 223Fr is found in nature in any noticeable quantities. Using the law of radioactive decay, one can calculate that a gram of natural uranium contains 4 · 10–18 g of 223Fr. And this means that in radioactive equilibrium with the entire mass of terrestrial uranium there is about 500 g of France-223. In vanishingly small quantities on Earth there are two more isotopes of element 87 - 224Fr (a member of the radioactive family of thorium) and 221Fr. Naturally, it is almost impossible to find an element on Earth whose world reserves do not reach a kilogram. Therefore, all studies of France and its few compounds were carried out on artificial products.

Sodium in a submarine

Rubidium is a radioactive element, it slowly emits a stream of electrons, turning into strontium.

The most remarkable property of rubidium is its peculiar sensitivity to light. Under the influence of light rays, rubidium becomes a source of electric current. With the cessation of light irradiation, the current also disappears.

R. reacts with water explosively, and hydrogen is liberated and a solution of R. hydroxide, RbOH, is formed.

Rubidium did not pass by its attention and many representatives of the plant world: traces of it are found in seaweed and tobacco, in tea leaves and coffee beans, in sugar cane and beets, in grapes and some types of citrus fruits.

Why was it called rubidium? Rubidus - Latin for "red". It would seem that this name is more suitable for copper than rubidium of very ordinary color. But let's not jump to conclusions.

This name was given to element 37 by its discoverers Kirchhoff and Bunsen. More than a hundred years ago, while studying various minerals with a spectroscope, they noticed that one of the samples of lepidolite, sent from Rosen, Saxony, showed special lines in the dark red region of the spectrum. These lines were not found in the spectra of any known substance. Soon, similar dark red lines were found in the spectrum of the sediment obtained after the evaporation of medicinal waters from the Black Forest mineral springs. It was natural to assume that these lines belong to some new, previously unknown element. So in 1861 rubidium was discovered

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Distance Education Center for Disabled Children at OGAOU "Belgorod Engineering Youth Boarding School" ALKALINE METALS Completed by: O.S. Bykova, chemistry teacher

Purpose: to repeat the properties of metals, systematize and deepen knowledge about alkali metals based on their comparative characteristics... Form an understanding of the physical and chemical properties of alkali metals.

The structure and properties of atoms

Alkali metals are elements of the main subgroup of group I: lithium Li, sodium Na, potassium K, rubidium Rb, cesium Cs, francium Fr.

At the external energy level, the atoms of these elements each contain one electron, located at a relatively large distance from the nucleus. They easily donate this electron, therefore they are very strong reducing agents. In all their compounds, alkali metals exhibit an oxidation state of +1. Their reducing properties are enhanced upon going from Li to Cs, which is associated with an increase in the radii of their atoms. These are the most typical representatives of metals: their metallic properties are especially pronounced.

Alkali metals - simple substances

Silvery-white soft substances (cut with a knife), with a characteristic sheen on the freshly cut surface. All of them are light and fusible, and, as a rule, their density increases from Li to Cs, and the melting point, on the contrary, decreases.

Chemical properties

All alkali metals are extremely active, in all chemical reactions exhibit reducing properties, donate their only valence electron, turning into a positively charged cation. Simple substances can act as oxidants - non-metals, oxides, acids, salts, organic substances.

Interaction with non-metals

Alkali metals easily react with oxygen, but each metal shows its individuality: oxide forms only lithium: 4Li + O2 = 2Li2O, sodium forms peroxide: 2Na + O2 = Na2O2, potassium, rubidium and cesium - superoxide: K + O2 = KO2.

Interaction with hydrogen, sulfur, phosphorus, carbon, silicon occurs when heated: with hydrogen, hydrides are formed: 2Na + H2 = 2NaH, with sulfur - sulfides: 2K + S = K2S, with phosphorus - phosphides: 3K + P = K3P, with silicon - silicides: 4Cs + Si = Cs4Si, with carbon carbides form lithium and sodium: 2Li + 2C = Li2C2

Only lithium easily reacts with nitrogen, the reaction proceeds at room temperature with the formation of lithium nitride: 6Li + N2 = 2Li3N. With halogens, all alkali metals form halides: 2Na + Cl2 = 2NaCl.

Interaction with water

All alkali metals react with water, lithium reacts calmly, staying on the surface of the water, sodium often ignites, and potassium, rubidium and cesium react explosively:

Alkali metals are capable of reacting with dilute acids with the evolution of hydrogen, but the reaction will be ambiguous, since the metal will react with water, and then the resulting alkali will be neutralized by the acid. When interacting with oxidizing acids, for example, nitric acid, an acid reduction product is formed, although the course of the reaction is also ambiguous. The interaction of alkali metals with acids is almost always accompanied by an explosion, and such reactions are not carried out in practice. 5interaction with acids

Alkali metal compounds Alkali metals do not occur in free form in nature due to their extremely high chemical activity. Some of their natural compounds, in particular sodium and potassium salts, are quite widespread; they are found in many minerals, plants, and natural waters.

Sodium hydroxide NaOH is known in technology under the names of caustic soda, caustic soda, caustic. The technical name for potassium hydroxide KOH is caustic potassium. Both hydroxides - NaOH and KOH corrode fabrics and paper, therefore they are also called caustic alkalis. Caustic soda is used in large quantities for refining petroleum products, in paper and textile industry, for the production of soap and fibers. Caustic potassium is more expensive and less commonly used. Its main area of ​​application is production liquid soap.

Alkali metal salts are solid crystalline substances of ionic structure. ... Na2CO3 - sodium carbonate, forms crystalline hydrate Na2CO3 * 10H2O, known as crystalline soda, which is used in the production of glass, paper, soap. In everyday life you are more familiar with acidic salt - sodium bicarbonate NаHCO3, it is used in Food Industry(baking soda) and in medicine (baking soda). К2С03 - potassium carbonate, technical name - potash, used in the production of liquid soap. Na2SO4 10H2O - sodium sulfate crystalline hydrate, technical name - Glauber's salt, is used for the production of soda and glass and as a laxative.

NaCl - sodium chloride, or table salt, this salt is well known to you from the course of last year. Sodium chloride is the most important raw material in chemical industry, is widely used in everyday life.

Thank you for your attention!