Instructions
Take the periodic table, and using a ruler, draw a line that starts in the cell with the element Be (Beryllium) and ends in the cell with the element At (Astatine).
Those elements that will be to the left of this line are metals. Moreover, the “lower and to the left” the element is located, the more pronounced metallic properties it has. It is easy to see that in the periodic table such a metal is (Fr) - the most active alkali metal.
Accordingly, those elements to the right of the line have properties. And here, too, a similar rule applies: the “higher and to the right” of the line the element is, the stronger the non-metal it is. Such an element in the periodic table is fluorine (F), the strongest oxidizing agent. He is so active that chemists used to give him a respectful, albeit unofficial, name: “Everything chews.”
Questions may arise such as “What about those elements that are on the line itself or very close to it?” Or, for example, “To the right and above the line are chrome, . Are these really non-metals? After all, they are used in steel production as alloying additives. But it is known that even small impurities of non-metals make them brittle.” The fact is that the elements located on the line itself (for example, aluminum, germanium, niobium, antimony) have, that is, a dual character.
As for, for example, vanadium, chromium, manganese, the properties of their compounds depend on the oxidation state of the atoms of these elements. For example, their higher oxides, such as V2O5, CrO3, Mn2O7, have pronounced . That is why they are located in seemingly “illogical” places in the periodic table. In their “pure” form, these elements are, of course, metals and have all the properties of metals.
Sources:
- metals in the periodic table
For schoolchildren studying the table Mendeleev - horrible dream. Even the thirty-six elements that teachers usually assign result in hours of grueling cramming and headaches. Many people don’t even believe what to learn table Mendeleev is real. But the use of mnemonics can make life much easier for students.
Instructions
Understand the theory and choose the right technique Rules that make it easier to memorize the material, mnemonic. Their main trick is the creation of associative connections, when abstract information is packaged into a bright picture, sound or even smell. There are several mnemonic techniques. For example, you can write a story from elements of memorized information, look for consonant words (rubidium - switch, cesium - Julius Caesar), turn on spatial imagination, or simply rhyme the elements of the periodic table.
The Ballad of Nitrogen It is better to rhyme the elements of Mendeleev’s periodic table with meaning, according to certain characteristics: by valency, for example. So, alkaline ones rhyme very easily and sound like a song: “Lithium, potassium, sodium, rubidium, cesium francium.” “Magnesium, calcium, zinc and barium - their valence is equal to a pair” is an unfading classic of school folklore. On the same topic: “Sodium, potassium, silver are monovalent goodness” and “Sodium, potassium and argentum are monovalent.” Creativity, unlike cramming, which lasts for a couple of days at most, stimulates long-term memory. This means more about aluminum, poems about nitrogen and songs about valence - and memorization will go like clockwork.
Acid thriller To make it easier to memorize, an idea is invented in which elements of the periodic table are transformed into heroes, landscape details or plot elements. For example, everyone famous text: “The Asian (Nitrogen) began to pour (Lithium) water (Hydrogen) into Pinery(Bohr). But it was not he (Neon) that we needed, but Magnolia (Magnesium).” It can be supplemented with the story of a Ferrari (iron - ferrum), in which the secret agent "Chlorine zero seventeen" (17 - serial number of chlorine) was traveling to catch the maniac Arseny (arsenic - arsenicum), who had 33 teeth (33 - serial number arsenic), but something sour got into his mouth (oxygen), it was eight poisoned bullets (8 is the serial number of oxygen)... We can continue ad infinitum. By the way, a novel written based on the periodic table can be assigned to a literature teacher as an experimental text. She'll probably like it.
Build a memory palace This is one of the names quite effective technology memorization when spatial thinking is activated. Its secret is that we can all easily describe our room or the path from home to the store, school, etc. In order to create a sequence of elements, you need to place them along the road (or in the room), and present each element very clearly, visibly, tangibly. Here is a skinny blond with a long face. The hard worker who lays tiles is silicon. A group of aristocrats in an expensive car - inert gases. And, of course, helium balloons.
note
There is no need to force yourself to remember the information on the cards. The best thing is to associate each element with a certain bright image. Silicon - with Silicon Valley. Lithium - with lithium batteries in mobile phone. There can be many options. But the combination visual image, mechanical memorization, tactile sensation from a rough or, conversely, smooth glossy card, will help you easily pick up the most the smallest details from the depths of memory.
You can draw the same cards with information about the elements that Mendeleev had in his time, but only supplement them with modern information: the number of electrons at the external level, for example. All you need to do is lay them out before going to bed.
Sources:
- Mnemonic rules for chemistry
- how to remember the periodic table
The problem of definition is far from idle. It will hardly be pleasant if in a jewelry store they want to give you an outright fake instead of an expensive gold item. Isn’t it of interest from which metal Was it a broken car part or a found antique?
Instructions
Here, for example, is how the presence of copper in an alloy is determined. Apply to cleaned surface metal drop (1:1) nitric acid. As a result of the reaction, gas will begin to be released. After a few seconds, blot the drop with filter paper, then hold it over where the concentrated ammonia solution is located. The copper will react, turning the stain a dark blue color.
Here's how to tell bronze from brass. Place a piece of metal shavings or sawdust in a beaker with 10 ml of a solution (1:1) of nitric acid and cover it with glass. Wait a little until it completely dissolves, and then heat the resulting liquid almost to a boil for 10-12 minutes. A white residue will remind you of bronze, but the beaker with brass will remain.
You can determine nickel in much the same way as copper. Apply a drop of nitric acid solution (1:1) to the surface metal and wait 10-15 seconds. Blot the drop with filter paper and then hold it over concentrated ammonia vapor. Apply a 1% solution of dimethylglyoxin in alcohol to the resulting dark spot.
Nickel will “signal” you with its characteristic red color. Lead can be determined using crystals of chromic acid and a drop of chilled acetic acid applied to it and, after a minute, a drop of water. If you see a yellow precipitate, you know it is lead chromate.
Determining the presence of iron is also easy. Take a piece metal and heat it in hydrochloric acid. If the result is positive, the contents of the flask should be colored yellow. If you are not good with chemistry, take a regular magnet. Know that all iron-containing alloys are attracted to it.
According to generally accepted views, acids are complex substances consisting of one or more hydrogen atoms that can be replaced by metal atoms and acidic residues. They are divided into oxygen-free and oxygen-containing, monobasic and polybasic, strong, weak, etc. How to determine whether a substance has acidic properties?
You will need
- - indicator paper or litmus solution;
- - hydrochloric acid (preferably diluted);
- - sodium carbonate powder (soda ash);
- - a little silver nitrate in solution;
- - flat-bottomed flasks or beakers.
Instructions
The first and simplest test is a test using indicator litmus paper or litmus solution. If paper strip or the solution has a pink tint, which means that the substance under study contains hydrogen ions, and this is a sure sign of acid. You can easily understand that the more intense the color (up to red-burgundy), the more acidic it is.
There are many other ways to check. For example, you are given the task of determining whether a clear liquid is hydrochloric acid. How to do it? You know the reaction to chloride ion. It is detected by adding even the smallest amounts of lapis solution - AgNO3.
Pour some of the test liquid into a separate container and drop in a little lapis solution. In this case, a “curdy” white precipitate of insoluble silver chloride will instantly form. That is, there is definitely a chloride ion in the molecule of the substance. But maybe it’s not, after all, but a solution of some kind of chlorine-containing salt? For example, sodium chloride?
Remember another property of acids. Strong acids (and hydrochloric acid, of course, is one of them) can displace weak acids from them. Place a little soda powder - Na2CO3 - in a flask or beaker and slowly add the liquid to be tested. If there is a hissing sound immediately and the powder literally “boils”, there will be no doubt left - it is hydrochloric acid.
Each element in the table is assigned a specific serial number (H - 1, Li - 2, Be - 3, etc.). This number corresponds to the nucleus (the number of protons in the nucleus) and the number of electrons orbiting the nucleus. The number of protons is thus equal to the number of electrons, which means that under normal conditions the atom is electrically .
The division into seven periods occurs according to the number of energy levels of the atom. Atoms of the first period have a single-level electron shell, the second - a two-level, the third - a three-level, etc. When a new energy level is filled, a new period begins.
The first elements of any period are characterized by atoms that have one electron at the outer level - these are alkali metal atoms. The periods end with atoms of noble gases, which have an external energy level completely filled with electrons: in the first period, noble gases have 2 electrons, in subsequent periods - 8. It is precisely because of the similar structure of the electron shells that groups of elements have similar physics.
In the table D.I. Mendeleev has 8 main subgroups. This number is determined by the maximum possible number of electrons at the energy level.
At the bottom periodic table lanthanides and actinides are isolated as independent series.
Using the table D.I. Mendeleev, one can observe the periodicity of the following properties of elements: atomic radius, atomic volume; ionization potential; electron affinity forces; electronegativity of the atom; ; physical properties potential connections.
Clearly traceable periodicity of the arrangement of elements in the table D.I. Mendeleev is rationally explained by the sequential nature of filling energy levels with electrons.
Sources:
- Mendeleev table
Periodic law, which is the basis of modern chemistry and explains the patterns of changes in the properties of chemical elements, was discovered by D.I. Mendeleev in 1869. Physical meaning This law is revealed when studying the complex structure of the atom.
In the 19th century it was believed that atomic mass is main characteristic element, so it was used to classify substances. Nowadays, atoms are defined and identified by the amount of charge on their nucleus (the number and atomic number on the periodic table). However, the atomic mass of elements, with some exceptions (for example, the atomic mass is less than the atomic mass of argon), increases in proportion to their nuclear charge.
With an increase in atomic mass, a periodic change in the properties of elements and their compounds is observed. These are the metallicity and non-metallicity of atoms, atomic radius, ionization potential, electron affinity, electronegativity, oxidation states, compounds (boiling points, melting points, density), their basicity, amphotericity or acidity.
How many elements are in the modern periodic table
The periodic table graphically expresses the law he discovered. The modern periodic table contains 112 chemical elements (the last ones are Meitnerium, Darmstadtium, Roentgenium and Copernicium). According to the latest data, the following 8 elements have also been discovered (up to 120 inclusive), but not all of them have received their names, and these elements are still few in any printed publications.
Each element occupies a specific cell in the periodic table and has its own serial number, corresponding to the charge of the nucleus of its atom.
How is the periodic table constructed?
The structure of the periodic table is represented by seven periods, ten rows and eight groups. Each period begins with an alkali metal and ends with a noble gas. The exceptions are the first period, which begins with hydrogen, and the seventh incomplete period.
Periods are divided into small and large. Small periods (first, second, third) consist of one horizontal row, large periods (fourth, fifth, sixth) - of two horizontal rows. The upper rows in large periods are called even, the lower rows are called odd.
In the sixth period of the table after (serial number 57) there are 14 elements similar in properties to lanthanum - lanthanides. They are listed at the bottom of the table as a separate line. The same applies to actinides located after actinium (with number 89) and largely repeating its properties.
The even rows of large periods (4, 6, 8, 10) are filled only with metals.
Elements in groups exhibit the same valency in oxides and other compounds, and this valency corresponds to the group number. The main ones contain elements of small and large periods, only large ones. From top to bottom they strengthen, non-metallic ones weaken. All atoms of side subgroups are metals.
The table of periodic chemical elements has become one of the major events in the history of science and brought to its creator, the Russian scientist Dmitry Mendeleev, world fame. This extraordinary man managed to combine all the chemical elements into a single concept, but how did he manage to open his famous table?
At room temperature (20 °C), all metals, except mercury, are in a solid state and conduct heat well. When cut, metals shine and some, like iron and nickel, have magnetic properties. Many metals are ductile - they can be made into wires - and forged - they can be easily shaped into different shapes.
Noble metals
Noble metals in the earth's crust are found in pure form, and not as part of compounds. These include copper, silver, gold and platinum. They are chemically passive and have difficulty interacting with others. Copper is a noble metal. Gold is one of the most inert elements. Due to their inertness, precious metals are not subject to corrosion, which is why they are used to make jewelry and coins. Gold is so inert that ancient gold items still shine brightly.
Alkali metals
Group 1 in the periodic table consists of 6 very active metals, incl. sodium and potassium. They melt at a relatively low temperature (the melting point of potassium is 64 ° C) and are so soft that they can be cut with a knife. When these metals react with water, they form an alkaline solution and are therefore called alkaline. Potassium reacts violently with water. At the same time, it is released, which burns with a lilac flame.
Alkaline earth metals
The six metals that make up Group 2 (including magnesium and calcium) are called alkaline earth metals. These metals are found in many minerals. Thus, calcium is found in calcite, veins of which can be found in limestone and chalk. Alkaline earth metals are less reactive than alkali metals, they are harder and melt at a higher temperature. Calcium is found in shells, bones and sponges. Magnesium is part of chlorophyll, the green pigment necessary for photosynthesis.
Metals of the 3rd and 4th groups
The seven metals in these groups are located to the right of the transition metals on the periodic table. Aluminum is one of the least dense metals, making it lightweight. But lead is very dense; It is used to make screens that protect against X-rays. All of these metals are quite soft and melt at a relatively low temperature. Many of them are used in alloys - mixtures of metals created for specific purposes. Bicycles and airplanes are made from aluminum alloys.
Transition metals
Transition metals have typical metallic properties. They are strong, hard, shiny and melt at high temperatures. They are less active than alkali and alkaline earth metals. These include iron, gold, silver, chromium, nickel, copper. They are all malleable and are widely used in industry - both in pure form and in the form of alloys. About 77% of the car's weight is made up of metals, mainly steel, i.e. an alloy of iron and carbon (see article ““). Wheel hubs are made of chrome-plated steel - for shine and protection against corrosion. The machine body is made of sheet steel. Steel bumpers protect the car in the event of a collision.
Activity series
The position of a metal in the activity series shows how readily the metal reacts. The more active a metal is, the more easily it takes oxygen away from less active metals. Active metals are difficult to isolate from compounds, while low-active metals are found in pure form. Potassium and sodium are stored in kerosene, as they instantly react with water and air. Copper is the least active and inexpensive metal. It is used in the production of pipes, tanks for hot water and electrical wires.
Metals and flame
Some metals, when brought close to a fire, give the flame a certain hue. By the color of the flame, you can determine the presence of a particular metal in the connection. To do this, a grain of the substance is placed in a flame at the end of a wire made of inert platinum. Sodium compounds color the flame yellow, copper compounds blue-green, calcium compounds red, and potassium compounds lilac. Fireworks contain different metals that create flames different shades. Barium gives green color, strontium is red, sodium is yellow, and copper is blue-green.
Corrosion
Corrosion is a chemical reaction that occurs when metal comes into contact with air or water. The metal reacts with oxygen in the air, and an oxide forms on its surface. The metal loses its luster and becomes coated. Highly reactive metals corrode faster than less reactive ones. Knights lubricated steel armor with oil or wax to prevent it from rusting (steel contains a lot of iron). To protect against rust, the steel body of a car is coated with several layers of paint. Some metals (for example, aluminum) are coated with a dense oxide film that protects them. When iron corrodes, it forms a loose oxide film, which, when reacted with water, produces rust. The rust layer easily crumbles, and the corrosion process spreads deeper. To protect against corrosion, steel cans are coated with a layer of tin, a less active metal. Large structures, such as bridges, are protected from corrosion by paint. Moving machine parts, such as bicycle chains, are lubricated with oil to prevent corrosion.
The method of protecting steel from corrosion by coating it with a layer of zinc is called galvanization. Zinc is more active than steel, so it “pulls” oxygen from it. Even if the zinc layer is scratched, oxygen in the air will react faster with the zinc than with the iron. To protect ships from corrosion, blocks of zinc or magnesium are attached to their hulls, which corrode themselves but protect the ship. For additional protection against corrosion, the steel sheets of the car body are cleanly galvanized before painting. WITH inside they are sometimes covered with plastic.
How metals were discovered
People probably learned how to obtain metals by accident, when metals were released from minerals when they were heated in furnaces with charcoal. Pure metal is released from the compound during a reduction reaction. 
The operation of blast furnaces is based on such reactions. Around 4000 BC The Sumerians (find out more in the article ““) made gold, silver and copper helmets and daggers. The earliest people learned to process copper, gold and silver, i.e. noble metals because they occur in their pure form. Around 3500 BC The Sumerians learned to make bronze - an alloy of copper and tin. Bronze is stronger than noble metals. Iron was discovered later, since extracting it from its compounds requires very high temperatures. The picture on the right shows a bronze ax (500 BC) and a Sumerian bronze bowl.
Before 1735, people knew only a few metals: copper, silver, gold, iron, mercury, tin, zinc, bismuth, antimony and lead. Aluminum was discovered in 1825. Today, scientists have synthesized a number of new metals by irradiating uranium with neutrons and other elementary particles in a nuclear reactor. These elements are unstable and decay very quickly.
If you remember even a little of your school physics course, you will easily remember that the most active metal is lithium. This fact is not surprising until you try to understand this issue in more detail. True, it is difficult to imagine a situation in which you would need such information, but for the sake of idle interest you can try.
For example, what is the activity of a metal? The ability to react quickly and completely with other chemical elements? Maybe. Then lithium, although it will be one of the most active metals, is clearly not a champion. But more on that later.
But if you make a minor clarification, say not “the most active metal”, but “the most electrochemically active metal”, then lithium will take its rightful first place.
Lithium
Translated from Greek, "lithium" means "stone". But this is not surprising, because the Swedish chemist Arfvedson discovered it in the stone, in the mineral petalite, which, among other things, contained this metal.
From that moment his study began. And there is something to work on. For example, its density is several times less than that of aluminum. He will, of course, drown in water, but in kerosene he will swim confidently.
Under normal conditions, lithium is a soft, silvery metal. In the Beketov series (a series of electrochemical activity), lithium occupies an honorable first place, even ahead of all other alkali metals. This means that when chemical reaction it will displace other metals, taking up vacant space in joints. This is what determines all its other properties.
For example, it is absolutely necessary for the normal functioning of the human body, albeit in tiny doses. An increased concentration can cause poisoning, a decreased concentration can cause mental instability.
Interestingly, the famous drink 7Up used to contain lithium and was positioned as a hangover cure. Perhaps it really helped.
Cesium
But if we get rid of the obsessive clarification “electrochemically”, leaving simply “active metal”, then cesium can be called the winner.
As you know, the activity of substances in the periodic table increases from right to left and from top to bottom. The fact is that in substances that are in the first group (first column), a single lonely electron rotates on the outer layer. It is easy for an atom to get rid of it, which is what happens in almost any reaction. If there were two of them, like the elements from the second group, then it would take more time, three - even more, and so on.
But even in the first group, the substances are not equally active. The lower a substance is, the larger the diameter of its atom, and the further away from the nucleus that single free electron spins. This means that the attraction of the nucleus has a weaker effect on it and it is easier for it to break away. Cesium meets all these conditions.
This metal was the first to be discovered using a spectroscope. Scientists examined the composition of mineral water from a healing spring and saw a bright blue band on the spectroscope, corresponding to a previously unknown element. Because of this, cesium got its name. It can be translated into Russian as “sky blue”.
Of all the pure metals that can be mined in significant quantities, cesium has the greatest chemical reactivity, as well as many other interesting properties. For example, it can melt in human hands. But to do this, it must be placed in a sealed glass capsule filled with pure argon, because otherwise it will simply ignite on contact with air. This metal has found its application in the most different areas: from medicine to optics.
France
And if we don’t stop at cesium and go even lower, we’ll end up with francium. It retains all the properties and features of cesium, but takes them to a qualitatively new level, because it has even more electron orbits, which means that that same lonely electron is even further from the center.
For a long time it was theoretically predicted and even described, but it was not possible to find it or find it, which is also not surprising, because in nature it is found in minute quantities (only astatine is less). And even if obtained, due to its high radioactivity and fast half-life, it remains extremely unstable.
Interestingly, the dream of medieval alchemists came true in France, only in reverse. They dreamed of obtaining gold from other substances, but here they use gold, which, after bombardment with electrons, turns into francium. But even so, it can be obtained in negligibly small quantities, insufficient even for careful study.
Thus, it is francium that remains the most active of the metals, far ahead of all the others. Only cesium can compete with it, and even then, solely due to a more significant amount. Even the most active nonmetal, fluorine, is significantly inferior to it.
In the section on the question Active metals, what are these metals? given by the author Olesya Oleskina the best answer is Those that give up electrons most easily.
The activity of metals in the periodic system increases from top to bottom and from right to left, thus the most active is francium, in the last layer of which there is 1 electron located quite far from the nucleus.
Active - alkali metals (Li, Na, K, Rb, Cs, Fr)
They are inferior to alkaline earths (Ca, Sr, BA, Ra)
Stirlitz
Artificial intelligence
(116389)
They are not classified as alkaline earths.
Answer from Natalia Kosenko[guru]
Those that react easily))
Answer from Teacher.[guru]
Rapidly oxidizing in air, sodium, potassium, lithium.
Answer from KSY[guru]
Eu, Sm, Li, Cs, Rb, K, Ra, Ba, Sr, Ca, Na, Ac, La, Ce, Pr, Nd, Pm, Gd, Tb, Mg, Y, Dy, Am, Ho, Er, Tm, Lu, Sc, Pu, Th, Np, U, Hf, Be, Al, Ti, Zr, Yb, Mn, V, Nb, Pa, Cr, Zn, Ga, Fe, Cd, In, Tl, Co, Ni, Te, Mo, Sn, Pb, H2, W, Sb, Bi, Ge, Re, Cu, Tc, Te, Rh, Po, Hg, Ag, Pd, Os, Ir, Pt, Au
Answer from Durchlaucht Furst[guru]
Alkali metals are elements of the main subgroup of group I of D. I. Mendeleev’s Periodic Table of Chemical Elements: lithium Li, sodium Na, potassium K, rubidium Rb, cesium Cs and francium Fr. These metals are called alkaline metals because most of their compounds are soluble in water. In Slavic, “leach” means “dissolve,” which determined the name of this group of metals. When alkali metals are dissolved in water, soluble hydroxides called alkalis are formed.
Due to the high chemical activity of alkali metals in relation to water, oxygen, and nitrogen, they are stored under a layer of kerosene. To react with an alkali metal, a piece the right size carefully cut off with a scalpel under a layer of kerosene, in an argon atmosphere the surface of the metal is thoroughly cleaned of the products of its interaction with air, and only then the sample is placed in a reaction vessel.
Anonymized metal bill on Wikipedia
Anonymized metal account
Common squirrel on Wikipedia
Look at the Wikipedia article about Common squirrel
Alkali metals on Wikipedia
Look at the Wikipedia article about Alkali metals
When people hear the word “metal,” they usually associate it with a cold, hard, conductive substance. electricity. However, metals and their alloys can differ greatly from each other. There are those that belong to the heavy group; these substances have the highest density. And some, for example, lithium, are so light that they could float in water if only they did not react actively with it.
Which metals are the most active?
But which metal exhibits the most intense properties? The most active metal is cesium. In terms of activity, it ranks first among all metals. Also considered to be his “brothers” are Francius, who is in second place, and Ununennius. But scientists still know little about the properties of the latter.
Properties of cesium
Cesium is an element that seems easy to melt in your hands. This, however, can be done only under one condition: if the cesium is in a glass ampoule. Otherwise, the metal can quickly react with the surrounding air and ignite. And the interaction of cesium with water is accompanied by an explosion - this is the most active metal in its manifestation. This answers the question of why it is so difficult to containerize cesium.
In order to place it inside a test tube, it must be made of special glass and filled with argon or hydrogen. The melting point of cesium is 28.7 o C. At room temperature, the metal is in a semi-liquid state. Cesium is a golden-white substance. In its liquid state, metal reflects light well. Cesium vapor has a greenish-blue tint.
How was cesium discovered?
The most active metal was the first chemical element, the presence of which in the surface of the earth's crust was discovered using the method of spectral analysis. When scientists received the spectrum of the metal, they saw two sky-blue lines in it. This is how this element got its name. The word caesius translated from Latin language means "sky blue".
History of discovery
Its discovery belongs to the German researchers R. Bunsen and G. Kirchhoff. Even then, scientists were interested in which metals were active and which were not. In 1860, researchers studied the composition of water from the Durkheim Reservoir. They did this using spectral analysis. In the water sample, scientists found elements such as strontium, magnesium, lithium, and calcium.
They then decided to analyze the drop of water using a spectroscope. That's when they saw two bright blue lines located not far from each other. One of them, in its position, practically coincided with the line of the metal strontium. Scientists decided that the substance they identified was unknown and classified it as an alkali metal.
In the same year, Bunsen wrote a letter to his photochemist colleague G. Roscoe, in which he talked about this discovery. Cesium was officially reported on May 10, 1860 at a meeting of scientists at the Berlin Academy. After six months, Bunsen was able to isolate about 50 grams of cesium chloroplatinite. Scientists processed 300 tons of mineral water and isolated about 1 kg of lithium chloride as a byproduct to ultimately obtain the most active metal. This suggests that mineral waters contain very little cesium.
The difficulty of obtaining cesium constantly pushes scientists to search for minerals containing it, one of which is pollucite. But the extraction of cesium from ores is always incomplete; during operation, cesium dissipates very quickly. This makes it one of the most difficult to obtain substances in metallurgy. The earth's crust, for example, contains 3.7 grams of cesium per ton. And in one liter of sea water, only 0.5 μg of the substance represents the most active metal. This makes cesium extraction one of the most labor-intensive processes.
Receipt in Russia
As stated, the main mineral from which cesium is obtained is pollucite. This most active metal can also be obtained from rare avogadrite. Pollucite is used in industry. Mining it after the breakup Soviet Union was not carried out in Russia, despite the fact that even in those days gigantic reserves of cesium were discovered in the Voronya tundra near Murmansk.
By the time the domestic industry could afford the extraction of cesium, the license to develop this deposit was acquired by a company from Canada. Currently, cesium extraction is carried out by the Novosibirsk company ZAO Rare Metals Plant.
Uses of cesium
This metal is used to make various solar cells. Cesium compounds are also used in special branches of optics - in the manufacture of infrared devices, Cesium is used in the manufacture of sights that allow you to notice enemy equipment and manpower. It is also used for making special metal halide lamps
But this does not exhaust the range of its application. A number of medical preparations have also been created based on cesium. These are medications for the treatment of diphtheria, peptic ulcers, shock and schizophrenia. Like lithium salts, cesium salts have normothimic properties - or, simply, they are able to stabilize the emotional background.
Francium metal
Another of the metals with the most intense properties is francium. It got its name in honor of the homeland of the discoverer of metal. M. Peret, born in France, discovered a new chemical element in 1939. It is one of those elements about which even chemist researchers themselves find it difficult to draw any conclusions.
Francium is the heaviest metal. Moreover, the most active metal is francium, along with cesium. Francium has this rare combination of high chemical activity and low nuclear resistance. Its longest-lived isotope has a half-life of only 22 minutes. Francium is used to detect another element, sea anemone. Francium salts were also previously proposed to be used to detect cancer tumors. However, due to its high cost, this salt is not profitable to produce.
Comparison of the most active metals
Ununenny is a metal that has not yet been discovered. It will occupy first place in the eighth row of the periodic table. The development and research of this element is carried out in Russia at the Joint Institute for Nuclear Research. This metal will also have to have very high activity. If we compare the already known francium and cesium, then francium will have the highest ionization potential - 380 kJ/mol.
For cesium this figure is 375 kJ/mol. But francium still does not react as quickly as cesium. Thus, cesium is the most active metal. This is an answer (chemistry is most often the subject in whose curriculum you can find a similar question), which can be useful both in a lesson at school and in a vocational school.
