The most reactive element in the Periodic Table is Fluorine. Despite the explosive properties of fluorine, it is a vital element for people and animals and is found in drinking water and toothpaste.

Just the facts

• Atomic number (number of protons in the nucleus) 9
• Atomic symbol (in the Periodic Table of Elements) F
• Atomic weight (average atomic mass) 18.998
• Density 0.001696 g/cm3
• At room temperature - gas
• Melting point minus 363.32 degrees Fahrenheit (- 219.62°C)
• Boiling point minus 306.62 degrees F (- 188.12°C)
• Number of isotopes (atoms of the same element with different numbers of neutrons) 18
• Most abundant F-19 isotopes (100% natural abundance)

Fluorite crystal

Chemists have been trying for years to liberate the element fluorine from various fluorides. However, fluorine is not free in nature: no chemical substance is capable of liberating fluorine from its compounds, due to its reactive nature.

The mineral fluorspar has been used for centuries to process metals. Calcium fluoride (CaF 2) was used to separate pure metal from unwanted minerals in the ore. “Fluer” (from the Latin word “fluere”) means “to flow”: the fluid properties of fluorspars made it possible to make metals. The mineral was also called Czech emerald because it was used in glass etching.

For many years, fluoride salts or fluorides were used for welding and glazing glass. For example, hydrofluoric acid was used to etch the glass of light bulbs.

Experimenting with fluorspar, scientists have studied its properties and composition for decades. Chemists often produced fluoric acid (fluoric acid, HF), an incredibly reactive and dangerous acid. Even small splashes of this acid on the skin could be fatal. Many scientists were injured, blinded, poisoned or died during experiments.

• In the early 19th century, Andre-Marie Ampère of France and Humphry Davy from England announced the discovery of a new element in 1813 and named it fluorine, following Ampère's suggestion.
• Henri Moisan, a French chemist, finally isolated fluorine in 1886 by electrolysis of dry potassium fluoride (KHF 2) and dry hydrofluoric acid, for which he was awarded the Nobel Prize in 1906.

From now on, fluorine is a vital element in nuclear energy. It is used to produce uranium hexafluoride, which is necessary for separating uranium isotopes. Sulfur hexafluoride is a gas used to insulate high-power transformers.

Chlorofluorocarbons (CFCs) were once used in aerosols, refrigerators, air conditioners, foam product packaging and fire extinguishers. These uses have been banned since 1996 because they contribute to ozone depletion. Until 2009, CFCs were used in inhalers to control asthma, but these types of inhalers were also banned in 2013.

Fluorine is used in many fluorinated substances, including solvents and high temperature plastics such as Teflon (poly-tetrafluoroethene, PTFE). Teflon is well known for its non-stick properties and is used in frying pans. Fluorine is also used for cable insulation, plumber's tape, and as a base for waterproof boots and clothing.

According to the Jefferson Laboratory, fluoride is added to city water supplies at a rate of one part per million to prevent tooth decay. Several fluoride compounds are added to toothpaste, also to prevent tooth decay.

Although all humans and animals are exposed to and need fluoride, the element fluoride in large enough doses is extremely toxic and dangerous. Fluoride can naturally be released into water, air, and onto vegetation and animal matter in small quantities. Large amounts of fluoride are found in some foods such as tea and shellfish.

While fluoride is essential for keeping our bones and teeth strong, too much can have the opposite effect, causing osteoporosis and tooth decay, and it can damage the kidneys, nerves and muscles.

In its gaseous form, fluoride is incredibly dangerous. Small amounts of fluoride gas cause eye and nose irritation, but large amounts can be fatal. Hydrofluoric acid is also fatal, even in small contact with skin.

Fluorine, the 13th most abundant element in the earth's crust; it usually settles in the soil and combines easily with sand, pebbles, coal and clay. Plants can absorb fluoride from the soil, although high concentrations cause plant death. For example, corn and apricot are among the plants most susceptible to damage when exposed to elevated concentrations of fluoride.

Who knew? Interesting facts about fluoride

• Sodium fluoride is rat poison.
• Fluorine is the most reactive element on our planet; it can explode on contact with any elements except oxygen, helium, neon and krypton.
• Fluorine is also the most electronegative element; it attracts electrons more easily than any other element.
• The average amount of fluoride in the human body is three milligrams.
• Fluorine is mainly mined in China, Mongolia, Russia, Mexico and South Africa.
• Fluorine is formed in solar stars at the end of their lives (“Astrophysical Journal in Letters” 2014). The element is formed at the highest pressures and temperatures inside a star as it expands to become a red giant. When the outer layers of a star are shed, creating a planetary nebula, fluorine moves along with other gases into the interstellar medium, eventually forming new stars and planets.
• About 25% of drugs and medications, including those for cancer, the central nervous system and the cardiovascular system, contain some form of fluoride.

According to a study (report in the Journal of Fluorine Chemistry) in the active components of drugs, replacement of carbon-hydrogen or carbon-oxygen bonds with carbon-fluorine bonds usually shows an improvement in the effectiveness of drugs, including increased metabolic stability, increased binding to molecules targets and improve membrane permeability.

According to this study, a new generation of anti-cancer drugs, as well as fluoride drug delivery probes, have been tested against cancer stem cells and have shown promise in the fight against cancer cells. The researchers found that the drugs that included fluoride were several times more potent and showed better stability than traditional cancer drugs.

How fluorine was discovered

AND The history of the discovery of fluorine is full of tragedy. Never before have so many sacrifices been made in attempts to discover new elements as in experiments aimed at isolating free fluorine. This story in general terms is as follows.

In 1670, the German chemist K. Schwankward noticed that if you take a vessel made of fluorspar with sulfuric acid and cover it with a glass plate, it will be corroded by the gases released.

In 1768, the scientist A. Margraf described hydrofluoric (hydrofluoric) acid, which was then studied in 1771 by K. Scheele.

Subsequently, K. Scheele and J. Priestley came to the conclusion that fluorspar is a calcium salt of an unknown acid, which Scheele proposed to call fluoride, and in 1779 he described a method for producing it in metal vessels. Thirty years later, J. Gay-Lussac and L. Thénard obtained anhydrous hydrofluoric acid.

The famous physicist A. Amper, having learned in 1810 about the work of G. Davy and that he was inclined to consider chlorine an element, suggested that in hydrofluoric acid there should be an element similar in its properties to chlorine and iodine, and that hydrofluoric acid itself An acid is a compound of hydrogen with a special element called fluorine. Davy fully agreed with this view.

Latin name fluor was derived from the Latin word fluo- leak. The reason for this name was the fact that hydrofluoric acid was obtained from a mineral known to G. Agricola under the name fluor lapis(fluorite – fluorspar – CaF 2). This mineral was used for a long time in the form of flux (flux), since when it is added to the charge, the melting point of the ores decreases.

The name “fluorine” was introduced around 1810 by Ampere, when he became more familiar with the properties of hydrofluoric acid. This word comes from the Greek phthoros– destructive. However, this name was accepted only by Russian chemists, and in all other countries the name “fluor” was retained.

M Numerous attempts to isolate fluorine remained unsuccessful for a long time due to the strong activity of the element, which at the moment of its isolation interacted with the walls of the vessel, water, etc.

Attempts to obtain free fluorine by oxidation of hydrofluoric acid not only ended in failure, but due to the strong toxicity of hydrogen fluoride resulted in several victims.

Two members of the Irish Academy of Sciences - brothers George and Thomas Knox - were the first victims of fluoride. They made a rather ingenious apparatus from fluorspar, but were unable to obtain free fluorine. Thomas Knox soon died from poisoning, and his brother George lost his ability to work and was forced to undergo treatment and rest in Naples for three years. The next victim was the chemist P. Layet from Brussels, who, knowing the consequences of the experiments of the Knox brothers, selflessly continued them and also paid with his life. The famous chemist J. Nickles from Nancy also suffered martyrdom. Gay-Lussac and Thénard suffered significantly from the effects on the lungs of small amounts of hydrogen fluoride. Davy's illness after 1814 is also attributed to hydrogen fluoride poisoning. These failures gave rise to G. Roscoe declaring that the problem of isolating free fluorine is “one of the most difficult problems of modern chemistry.”

But chemists still did not lose hope of isolating fluorine. Davy, for example, was definitely convinced that the production of fluorine could be successful if only the process was carried out in vessels made of feldspar.

An attempt to isolate fluorine was made by the French scientist E. Fremy, the teacher of A. Moissan. He prepared anhydrous hydrofluoric acid and wanted to obtain fluorine by electrolysis, but the gas did not evolve at the anode due to its strong activity.

In 1869, the English electrochemist G. Gore managed to obtain some free fluorine, but it instantly combined with hydrogen (with an explosion). This scientist tried dozens of substances as anodes (coal, platinum, palladium, gold, etc.), but could only establish that they were all destroyed by fluorine. At the same time, he came to the conclusion that it was necessary to lower the temperature of the electrolyzer in order to weaken the activity of fluorine.

Henri Moissan (1852–1907)

All these attempts were not in vain and were taken into account in subsequent systematic experiments by Moissan, a famous French chemist of the late 19th and early 20th centuries. Moissan built a U-shaped electrolyzer first from platinum, but later it turned out that it could also be made from copper, because the latter is coated with a thin layer of copper fluoride, which prevents further exposure to fluorine. Anhydrous hydrofluoric acid was taken as an electrolyte. But since this substance does not conduct electricity in an anhydrous state, a small amount of potassium hydrodifluoride KHF 2 was added to it. To obtain liquid hydrogen fluoride and reduce the activity of fluorine, the entire apparatus was immersed in a cooling mixture with ethyl chloride C2H5Cl, boiling at 12.5 °C. As a result, the apparatus was cooled to –23 °C. The electrodes were made of platinum or platinum iridide and were insulated with fluorspar plugs, which could not react with the fluorine released. To collect fluorine, other copper tubes were screwed on. Fluorine was first obtained in this device in 1886.

Two days later, Moissan notified the Paris Academy of Sciences about the discovery. “Various assumptions could be made about the nature of the gas released,” Moissan wrote in this statement. “The simplest would be to assume that we are dealing with fluorine, but it would also, of course, be possible that it is polyhydrogen fluoride or even a mixture of hydrofluoric acid and ozone, sufficiently active to explain the vigorous action which this gas exerts on crystalline silicic acid.”

Moissan's statement was accepted by the academy, and as determined by it, a special committee of reputable scientists was appointed to verify the discovery. During the test, Moissan's apparatus became capricious, and the experimenter could not even obtain a bubble of fluorine.

The story of the famous French chemist A.L. has been preserved. Le Chatelier about how Moissan first carried out experiments on the isolation of fluorine at the Paris Academy of Sciences.

“Having received a small corner for studying in Friedel’s laboratory at the New Sorbonne (University of Paris), Moissan some time later announced the successful completion of experiments on the production of elemental fluorine. Friedel was quick to report this to the Academy of Sciences. A special commission was created to familiarize itself with the works of Moissan, which met on a certain day for this purpose. Moissan began the experiment, but, to his great chagrin, the experiment was a failure: no fluorine was obtained.

When the commission left, Moissan and his assistant began to carefully analyze the entire progress of their work and look for the reason for the failure of the experiment. As a result, they came to the conclusion that this reason was, strange as it may seem, the dishes were washed too clean. That's why there were no traces of potassium fluoride left. It was enough for Moissan to add a little potassium fluoride to the liquid hydrogen fluoride in the device and pass an electric current, and free fluorine was immediately obtained.

The next day, Moissan received quite a sufficient amount of gas to convince the committee of the reality of his discovery. Moissan Fremy's teacher warmly congratulated him and said: “A teacher is always happy when he sees his students progress further and higher than himself.”

In 1925, a simpler method for producing fluorine was proposed. The electrolyte here is potassium bifluoride. The vessel for electrolysis in this case is made of copper or nickel, and the electrodes are made of different metals: the cathode is made of copper, and the anode is made of nickel. In a slightly modified form, this method is still used today.

1. People have not consumed inorganic fluoride for millions of years. Rat poison consists of 99.8% sodium fluoride, which is added to toothpaste, liquid soap, shampoos and drinking water. How could rat poison be of any use to humans? But people don't even think about it.

2. A good product does not need advertising. And all the advertising is about the benefits of chemicals. fluorine is a massive deception of humanity, which everyone can see, since according to its formula, inorganic fluorine is a real, powerful poison! Fluorine is a chemical substance of the second class of danger. "Ftoros" translated from Greek means "destroying." It is toxic if taken orally! Causes stomach pain, nausea, vomiting, diarrhea, salivation, difficulty breathing, weakness, trembling, heart attack, then convulsions and coma. Affects the kidneys and brain. Death occurs due to paralysis of the respiratory tract. The lethal dose is about 5-10 grams. Causes irritation upon contact with skin, pain and redness. In case of eye contact, ranges from irritation to serious eye damage. Long-term exposure to fluoride can damage bones (osteosclerosis), as well as fluorosis, which leads to bone fragility, weight loss, anemia, hardening (calcification) of ligaments, deterioration of general health and joint stiffness.

3. The number of people with caries in countries where they drink fluoridated water is no less than in those countries where fluoride is not used to add to drinks. In the book “Fluoride - the Big Deception” by the famous producer and BBC journalist Christopher Bryson, it is established that fluoride is a poison for bacteria. But fluoride is also so poisonous that it poisons not only bacteria, but also other cells of the body. It is advisable to consume sugar only in whole foods - nuts, fruits, dried fruits.

4. Only toothpaste and water without fluoride, and tooth whitening powders are safe for humans.

5. Fluorine is an extremely reactive non-metal and the most powerful oxidizing agent. It weakens the gums of your teeth!

6. Fluoride accelerates the aging of the human body! In his book Fluoride as an Aging Factor, Dr. J. Yamouyiannis writes: “The truth is that fluoridation is poisoning millions of people around the world.”

7. Most water fluoridation stations use aluminum sulfate and fluorides together. These two substances mix to form toxic aluminum fluoride. Aluminum is a foreign element for living organisms. It is practically not excreted from the body, is toxic to the kidneys, and when accumulated in the brain causes Alzheimer's disease.

8. Fluoride is one of the main reasons for the increase in cancer. In 1988, the Agonna National Laboratory (USA) published a study claiming that fluoride turns normal cells into cancer cells. In turn, Japanese doctor Tsutsui confirmed that under the influence of fluoride, normal cells not only turn into cancer cells, but also lead to genetic damage to cells, which suggests that it is harmful to pregnant women and leads to the birth of disabled children. Even government Research in the United States itself, after analyzing 156 cases of cancer deaths, led to the conclusion that fluoride accumulated in tissues causes both cancer and other fatal diseases. Research by the chief chemist at the US National Cancer Center, Dr. Dean Burke, showed that fluoride in toothpastes, as well as drinking fluoride, causes up to ten thousand deaths from cancer per year.

9. Water and dental fasting with fluoride lead to brittle teeth and bones. Drinking water with fluoride or from toothpaste is deposited in the human body and is concentrated, as a rule, in places where calcium accumulates, i.e. in bones and teeth. About 20-40 mg. fluoride per day suppresses the activity of the most important enzyme - phosphatase, which is necessary for calcium metabolism. As a result, the bones thicken, but become brittle and brittle.

10. When the production of atomic bombs was launched, as part of the “Manhattan Project”, toxic fluorides began to accumulate in huge quantities in landfills. So much toxic fluorides have accumulated in DuPont landfills in New Jersey that they are washed away by rain and begin to seep into the soil. Pets in the area began to die, all the plants withered, as a result of which indignant residents filed a lawsuit against the company. With the task of finding some “medicinal use” for fluorides, the DuPont concern hired famous lawyers and doctors. As a result, a widespread lie appeared and began to be replicated that fluoride supposedly strengthens teeth. As a result, the DuPont concern not only avoided trial, but also received an excellent opportunity, in the future, to get rid of toxic waste by selling it to us.

All over the world, billions of people drink and eat, with water and toothpaste, all this poison. Fluoride has never strengthened anyone's teeth.

11. Due to fluoride, the pineal gland is blocked and destroyed. The pineal gland regulates the release of melatonin, the “hormone of youth.” Research data from scientists shows that thyroid diseases began to increase just at the time when the benefits of fluoride began to be promoted. It is known that the thyroid gland in the body is responsible for many processes related to metabolism. Violation of its work leads to serious consequences for a person, one of which is obesity.

12. Because of fluoride, genetic disorders occur at the DNA level; women give birth to mentally retarded and sick children!

13. In the 21st century, toxic cheap substances began to be added to many toothpastes, shampoos and liquid soaps for the sake of making dirty money on people! The most commonly used waste products from the nuclear, aluminum and phosphate industries are sodium fluorosilicate (sodium silicofluoride), sodium fluoride (sodium fluoride), fluorosilicate acid.

14. Fluoride affects the kidneys, respiratory system, central nervous system, heart, bones, and circulatory system. Causes irritation to eyes, respiratory tract and skin. Irritation does not occur immediately.

15. A person who thoughtlessly spends money on toothpastes and fluoride water does not have an ounce of self-love. Wise people have been using fluoride-free toothpastes and tooth powders for a long time.

5 Products Added Toxic Inorganic Fluoride (Fluoride, Sodium Lauryl Sulfate (SLS), SLES)

1. Tooth powders.

2. Water with fluoride.

3. Detergents.

4. Skin washes.

5. Liquid soap.

6 types of replacement products without fluoride

1. Mustard instead of all chemical detergents.

2. White tooth powder instead of toothpastes.

3. Fluoride-free whitening powder

4. Products from Nature Clean. 99.9% natural ingredients, 0% toxic substances!

5. Phosphate-free washing powder Chistown.

6. Products of the company “SODASAN” (powders, detergents, shampoos, soaps, gels, fluoride-free toothpastes).

Harmful and dangerous components in cosmetics

Scientists have discovered many dangerous toxic substances in the list of ingredients used to produce cosmetics. The world's leading toxicologist, Epstein, speaks of 884 toxic substances, and other scientists have isolated larger numbers. Every year more than 1000 new chemical compounds appear, how many of them are also toxic? According to the EU Cosmetics Directive (Common European Cosmetics Regulations), out of 70,000 cosmetic components, only 3,000 are officially permitted in Europe. In Russia, the situation is completely different. Many of the components banned abroad in Russia are allowed for use in production, so even the composition of a jar of the same shampoo for the Russian and foreign markets can differ significantly.

Harmful and dangerous components in cosmetics: aggressive surfactants, sulfates

This includes:

• Sodium Lauryl Sulfate (SLS) - sodium sulfate, sodium lauryl sulfate
• Sodium Laureth Sulfate (SLES) - sodium sulfate, sodium laureth sulfate
• Ammonium Lauryl Sulfate (ALS) - ammonium lauryl sulfate
• Ammonium Laureth Sulfate – (ALES) - ammonium laureth sulfate
• Cocamide D.E.A.
• Cocomidopropyl Betaine
• And some other slightly milder surfactants

SLS and SLES, ALS and ALES are used in various cleansing products - liquid soap, shower gel, shampoo, face wash, bubble bath, toothpaste, etc. Dangerous toxic substances with strong degreasing and anti-corrosion properties. In addition to cosmetics, they are used in household and industrial cleaning and degreasing products, for example, for washing engines and garage floors. They accumulate in internal organs, in the liver, heart, kidneys, eyes, and other organs, and can cause cell mutation and various diseases. Particularly dangerous for children. They cause dryness, irritation and flaking of the skin, dry out the hair, weaken the hair follicle, and cause diseases of the scalp and body. Promotes skin aging. Reacting with other cosmetic components and nitrates in the blood, they form carcinogens.

Please note that if the packaging of a shampoo or other product says “without SLS”, this does not mean that there are no other harmful and dangerous ingredients, such as ammonium lauryl sulfate, for example.

The most active, the most electronegative, the most reactive, the most aggressive element, the most non-metal. The most, the most, the most... We will have to repeat this word or its synonyms very often.

After all, we are talking about fluoride.

At the pole of the periodic table

Fluorine is an element from the halogen family, which also includes chlorine, bromine, iodine and artificially produced radioactive astatine. Fluorine has all the features of its fellow subgroups, but it is like a person without a sense of proportion: everything is increased to the extreme, to the limit. This is explained primarily by the position of element No. 9 in the periodic table and its electronic structure. Its place in the periodic table is the “pole of non-metallic properties”, upper right corner. Atomic model of fluorine: nuclear charge 9+, two electrons are located on the inner shell, seven on the outer shell. Each atom always strives for a stable state. To do this, it needs to fill the outer electronic layer. The fluorine atom in this sense is no exception. The eighth electron is captured, and the goal is achieved - a fluorine ion with a “saturated” outer shell is formed.

The number of electrons attached shows that the negative valence of fluorine is 1-; Unlike other halogens, fluorine cannot exhibit a positive valence.

The tendency of fluorine to fill the outer electron layer to an eight-electron configuration is extremely strong. Therefore, it has extraordinary reactivity and forms compounds with almost all elements. As recently as the 1950s, most chemists believed, and with good reason, that noble gases could not form true chemical compounds. However, soon three of the six reclusive elements could not resist the onslaught of surprisingly aggressive fluorine. Since 1962, fluorides have been obtained, and through them, other compounds of krypton, xenon and radon.

It is very difficult to keep fluorine from reacting, but it is often no easier to remove its atoms from compounds. Another factor plays a role here - the very small sizes of the fluorine atom and ion. They are about one and a half times less than chlorine, and half as much as iodine.

The effect of the size of the halogen atom on the stability of halides can be easily observed using the example of molybdenum halide compounds (Table 1).

Table 1

Obviously, the larger the size of the halogen atoms, the fewer of them are located around the molybdenum atom. The maximum possible valency of molybdenum is realized only in combination with fluorine atoms, the small size of which allows the molecule to be “packed” most tightly.

Fluorine atoms have very high electronegativity, i.e. the ability to attract electrons; When interacting with oxygen, fluorine forms compounds in which the oxygen is positively charged. Hot water burns in a stream of fluorine to form oxygen. Isn't it an exceptional case? Oxygen suddenly turned out to be not a cause, but a consequence of combustion.

Not only water, but also other usually non-combustible materials, such as asbestos, brick, and many metals, ignite in a fluorine stream. Bromine, iodine, sulfur, selenium, tellurium, phosphorus, arsenic, antimony, silicon, charcoal spontaneously ignite in fluorine even at ordinary temperatures, and with slight heating the same fate befalls the noble platinum metals, known for their chemical passivity.

Therefore, the name fluorine itself is not surprising. Translated from Greek, this word means “destroying.”

Fluorine or fluorine?

Fluorine - destructive - a surprisingly appropriate name. However, another name for element No. 9 is more common abroad - fluor, which means “fluid” in Latin.

This name is more suitable not for fluorine, but for some of its compounds and originates from fluorite or fluorspar - the first fluorine compound used by man. Apparently, even in ancient times, people knew about the ability of this mineral to reduce the melting point of ores and metallurgical slags, but, naturally, they did not know its composition. The main component of this mineral, a still unknown element, was called fluor.

This name is so ingrained in the minds of scientists that a logically justified proposal to rename the element, put forward in 1816, did not find support. But during these years there was an intensified search for fluor; a lot of experimental data had already been accumulated that confirmed the destructive abilities of fluor and its compounds. And the authors of the proposal were not just anyone, but the largest scientists of that time, Andre Ampère and Humphry Davy. And yet fluorine remained fluorine.

Victims? - No, heroes

The first mention of fluor and fluorite dates back to the 15th century.

At the beginning of the 18th century. Hydrofluoric acid, an aqueous solution of hydrogen fluoride, was discovered, and in 1780 the famous Swedish chemist Karl Wilhelm Scheele first suggested that this acid contained a new active element. However, to confirm Scheele’s guess and isolate fluorine (or fluorine), it took chemists more than 100 years, a whole century of hard work by many scientists from different countries.

Today we know that fluorine is very toxic and that working with it and its compounds requires great care and thoughtful protective measures. The discoverers of fluorine could only guess about this, and even then not always. Therefore, the history of the discovery of fluorine is associated with the names of many heroes of science. English chemists brothers Thomas and George Knox tried to obtain fluorine from fluorides of silver and lead. The experiments ended tragically: Georg Knox became disabled, Thomas died. The same fate befell D. Nickles and P. Layet. Outstanding chemist of the 19th century. Humphry Davy, the creator of the hydrogen theory of acids, the man who first obtained sodium, potassium, magnesium, calcium, strontium and barium, who proved the elemental nature of chlorine, was unable to solve the problem of obtaining the all-destructive element. During these experiments, he was poisoned and became seriously ill. J. Gay-Lussac and L. Tenard lost their health without achieving any encouraging results.

A. Lavoisier, M. Faraday, E. Fremy were more successful. Fluorine “spared” them, but they were not successful either.

In 1834, Faraday thought that he had finally succeeded in obtaining the elusive gas. But he was soon forced to admit: “I couldn’t get fluoride. My assumptions, subjected to strict analysis, fell away one after another...” For 50 (!) years, this giant of science tried to solve the problem of obtaining fluorine, but was never able to overcome it...

Failures plagued scientists, but confidence in the existence and possibility of isolating fluorine grew stronger with each new experiment. It was based on numerous analogies in the behavior and properties of fluorine compounds with compounds of already known halogens - chlorine, bromine and iodine.

There were some successes along the way. Fremy, trying to extract fluorine from fluorides using electrolysis, found a way to produce anhydrous hydrogen fluoride. Each experience, even unsuccessful ones, replenished the knowledge base about the amazing element and brought the day of its discovery closer. And this day has come.

On June 26, 1886, French chemist Henri Moissan electrolyzed anhydrous hydrogen fluoride. At a temperature of -23°C, he obtained a new, extremely reactive gaseous substance at the anode. Moissan managed to collect several gas bubbles. It was fluoride!

Moissan reported his discovery to the Paris Academy. A commission was immediately created, which in a few days was supposed to arrive at Moissan’s laboratory to see everything with its own eyes.

Moissan carefully prepared for the repeat experiment. He subjected the original hydrogen fluoride to additional purification, and... the high-ranking commission did not see fluorine. The experiment was not reproduced; electrolysis with the release of fluorine was not observed! Scandal?!

But Moissan managed to find the reason. It turned out that only small amounts of potassium fluoride contained in hydrogen fluoride make it a conductor of electricity. The use of hydrogen fluoride in the first experiment without additional purification ensured success: there were impurities - electrolysis took place. The careful preparation of the second experiment was the reason for the failure.

Still, luck was definitely on Moissan's side. Soon he managed to find inexpensive and reliable material for devices in which fluorine is produced. This problem was no less difficult than obtaining a recalcitrant element. Hydrogen fluoride and fluorine destroyed any equipment. Davy also tested vessels made of crystalline sulfur, coal, silver and platinum, but all these materials were destroyed during the electrolysis of fluorine compounds.

Moissan obtained the first grams of fluorine in a platinum electrolyzer with electrodes made of an iridium-platinum alloy. Despite the low temperature at which the experiment was carried out, each gram of fluorine “destroyed” 5...6 g of platinum.

Moissan replaced the platinum vessel with a copper one. Of course, copper is also susceptible to the action of fluorine, but just as aluminum is protected from air by an oxide film, so copper was “hidden” from fluorine behind a film of copper fluoride that was irresistible to it.

Electrolysis is still practically the only method for producing fluorine. Since 1919, bifluoride melts have been used as an electrolyte. The materials of modern electrolyzers and electrodes are copper, nickel, steel, and graphite. All this made the production of element No. 9 many times cheaper and made it possible to produce it on an industrial scale. However, the principle of obtaining fluorine remained the same as that proposed by Davy and Faraday and first implemented by Moissan.

Fluorine and many of its compounds are not only of great theoretical interest, but also find wide practical application. There are a lot of fluorine compounds, their use is so versatile and extensive that even 100 pages would not be enough to tell about everything interesting that is associated with this element. Therefore, in our story you will find only the most interesting fluoride compounds that have become firmly established in our industry, in our lives, in our everyday life and even in our art - compounds without which (this can be said without exaggeration) progress is unthinkable.

Fluorine hydride and... water

What can all-destructive fluorine and “peaceful” familiar water have in common? It would seem - nothing. But let's beware of hasty conclusions. After all, water can be considered as an oxygen hydride, and hydrofluoric acid HF is nothing more than a fluorine hydride. So, we are dealing with the closest chemical “relatives” - hydrides of two strong oxidizing agents.

Hydrides of all halogens are known. Their properties change naturally, but hydrogen fluoride is in many ways closer to water than to other hydrogen halides. Compare the dielectric constants: for HF and H 2 O they are very close (83.5 and 80), while for bromine, iodine and chlorine hydrides this characteristic is much lower (only 2.9...4.6). The boiling point of HF is +19°C, while HI, HBr and HCl turn into a gaseous state already at sub-zero temperatures.

One of the natural fluorine compounds, the mineral cryolite, is called unmelting ice. Indeed, huge cryolite crystals are very similar to ice blocks.

In one of the stories of science fiction writer I.A. Efremov describes a meeting in space with the inhabitants of a planet on which fluorine, rather than oxygen, participates in all vital oxidative processes. If such a planet exists, then there is no doubt that its inhabitants quench their thirst... with hydrogen fluoride.

On Earth, hydrogen fluoride serves other purposes.

Back in 1670, the Nuremberg artist Schwangard mixed fluorspar with sulfuric acid and applied drawings to glass with this mixture. Schwangard did not know that the components of his mixture reacted with each other, but “drew” the reaction product. This did not prevent the implementation of Schwangard's discovery. They still use it today. A thin layer of paraffin is applied to the glass vessel. The artist paints over this layer and then dips the vessel into a solution of hydrofluoric acid. In those places where the paraffin “armor”, invulnerable to hydrogen fluoride, is removed, the acid corrodes the glass, and the design is forever imprinted on it. This is the oldest use of hydrogen fluoride, but by no means the only one.

Suffice it to say that less than 20 years after the creation of the first industrial installations for the production of hydrogen fluoride, its annual production in the USA reached 125 thousand tons.

Glass, food, oil, nuclear, metallurgical, chemical, aviation, paper - this is not a complete list of those industries where hydrogen fluoride is widely used.

Hydrogen fluoride is capable of changing the rate of many reactions and is used as a catalyst for a wide variety of chemical transformations.

One of the main trends in modern chemistry is to conduct reactions in non-aqueous media. Hydrogen fluoride has become the most interesting and already widely used non-aqueous solvent.

Hydrogen fluoride is a very aggressive and dangerous reagent, but it is indispensable in many branches of modern industry. Therefore, the methods of handling it have been so improved that for a competent chemist of our day, hydrogen fluoride has become almost as safe as for the inhabitants of an unknown fluorine planet.

Fluorine and metallurgy

Aluminum is the most common metal in the earth's crust, its reserves are huge, but aluminum production began to develop only at the end of the last century. The oxygen compounds of aluminum are very strong, and their reduction with coal does not produce pure metal. And to produce aluminum by electrolysis, its halogen compounds are required and, above all, cryolite, which contains both aluminum and fluorine. But there is little cryolite in nature; in addition, it has a low content of “winged metal” - only 13%. This is almost three times less than in bauxite. Recycling bauxite is difficult, but fortunately it can dissolve in cryolite. This produces a low-melting and aluminum-rich melt. Its electrolysis is the only industrial method for producing aluminum. The lack of natural cryolite is compensated by artificial cryolite, which is produced in huge quantities using hydrogen fluoride.

Thus, our achievements in the development of the aluminum industry and in aircraft construction are to a large extent a consequence of the successes in the chemistry of fluorine and its compounds.

A few words about organofluorine

In the 30s of our century, the first compounds of fluorine and carbon were synthesized. In nature, such substances are extremely rare, and no special advantages have been noticed for them.

However, the development of many branches of modern technology and their need for new materials has led to the fact that today there are already thousands of organic compounds that contain fluorine. It is enough to recall freons - the most important materials for refrigeration equipment, and fluoroplastic-4, which is rightly called plastic platinum.

Separate notes are devoted to these materials. In the meantime, we will move on to the next chapter, which is called...

Fluorine and life

It would seem that such a phrase is not entirely legal. The “character” of element No. 9 is very aggressive; his story resembles a detective novel, where every page is poisoning or murder. In addition, fluorine itself and many of its compounds were used to produce weapons of mass destruction: in the Second World War, the Germans used chlorine trifluoride as an incendiary agent; Several fluorine-containing compounds were considered in the USA, England and Germany as secret poisonous substances and were produced on a semi-factory scale. It is no secret that without fluorine it would hardly have been possible to obtain atomic weapons.

Working with fluoride is dangerous: the slightest carelessness can result in a person’s teeth being destroyed, nails becoming disfigured, bone fragility increasing, blood vessels losing their elasticity and becoming brittle. The result is severe illness or death.

And yet the title “Fluorine and Life” is justified. This was first proven... by an elephant. Yes, yes - an elephant. An ordinary, albeit fossil, elephant found in the vicinity of Rome. Fluoride was accidentally discovered in his teeth. This discovery prompted scientists to conduct a systematic study of the chemical composition of human and animal teeth. It was found that teeth contain up to 0.02% fluoride, which enters the body with drinking water. Typically, a ton of water contains up to 0.2 mg of fluoride. Lack of fluoride leads to tooth decay - caries.

The artificial addition of fluoride to water in those places where its deficiency is found leads to the elimination of new cases of the disease and a reduction in caries in sick people. Let's make a reservation right away - a large excess of fluoride in water causes an acute disease - fluorosis (spotted enamel). The eternal dilemma of medicine: large doses are poison, small doses are medicine.

In many places, installations for artificial fluoridation of water have been built.

This method of preventing caries in children is especially effective. Therefore, in some countries, fluoride compounds (in extremely small doses) are added to... milk.

There is an assumption that fluorine is necessary for the development of a living cell and that it is included, together with phosphorus, in animal and plant tissues.

Fluorine is widely used in the synthesis of various medications. Organofluorine compounds are successfully used to treat thyroid diseases, especially Graves' disease, chronic forms of diabetes, bronchial and rheumatic diseases, glaucoma and cancer. They are also useful in the prevention and treatment of malaria and are a good remedy against streptococcal and staphylococcal infections. Some organofluorine drugs are reliable pain relievers.

Fluorine and life - it is this section of fluorine chemistry that is worthy of the greatest development, and the future lies with it. Fluoride and death? It is possible and necessary to work in this area, but in order to obtain not deadly toxic substances, but various drugs to combat rodents and other agricultural pests. Examples of such applications include monofluoroacetic acid and sodium fluoroacetate.

And ice and fire

How nice it is to take a bottle of ice-cold mineral water out of the refrigerator on a hot summer day...

In most refrigerators - both industrial and domestic - the refrigerant, the substance that creates cold, is an organofluorine liquid - freon.

Freons are obtained by replacing hydrogen atoms in the molecules of the simplest organic compounds with fluorine or fluorine and chlorine.

table 2

The simplest hydrocarbon is methane CH4. If all the hydrogen atoms in methane are replaced with fluorine, then tetrafluoromethane CF 4 (Freon-14) is formed, and if only two hydrogen atoms are replaced with fluorine, and the other two with chlorine, then difluorodichloromethane CF 2 Cl 2 (Freon-12) is obtained. In table 2 shows the most important characteristics of several such compounds.

Home refrigerators usually use Freon-12. It is a colorless, water-insoluble and non-flammable gas with an odor similar to ether. Freons 11 and 12 also work in air conditioning units. In the “scale of harmfulness” compiled for all used refrigerants, freons occupy the last places. They are even more harmless than “dry ice” - solid carbon dioxide.

Freons are extremely stable and chemically inert. Here, as in the case of fluoroplastic, we are faced with the same amazing phenomenon: with the help of the most active element - fluorine - it is possible to obtain chemically very passive substances. They are especially resistant to the action of oxidizing agents, and this is not surprising - after all, their carbon atoms are in the highest state of oxidation. Therefore, fluorocarbons (and, in particular, freons) do not burn even in an atmosphere of pure oxygen. With strong heating, destruction occurs - the disintegration of molecules, but not their oxidation. These properties make it possible to use freons in a number of other cases: they are used as flame arresters, inert solvents, and intermediate products for the production of plastics and lubricants.

Thousands of organofluorine compounds of various types are now known. Many of them are used in the most important branches of modern technology.

In freons, fluorine works for the “cold industry”, but with its help it is possible to obtain very high temperatures. Compare these figures: the temperature of the oxygen-hydrogen flame is 2800°C, the oxygen-acetylene flame is 3500°C, and when hydrogen burns in fluorine, a temperature of 3700°C develops. This reaction has already found practical application in hydrogen fluoride torches for cutting metal. In addition, burners are known that operate on fluorochlorides (compounds of fluorine and chlorine), as well as on a mixture of nitrogen trifluoride and hydrogen. The latter mixture is especially convenient, since nitrogen trifluoride does not cause corrosion of equipment. Naturally, in all these reactions fluorine and its compounds play the role of an oxidizing agent. They can also be used as an oxidizer in liquid jet engines. A lot speaks in favor of a reaction involving fluorine and its compounds. A higher temperature develops, which means that the pressure in the combustion chamber will be greater, and the thrust of the jet engine will increase. No solid combustion products are formed as a result of such reactions, which means that in this case there is also no danger of clogging the nozzles and rupturing the engine.

But fluorine, as a component of rocket fuel, has a number of major disadvantages. It is highly toxic, corrosive and has a very low boiling point. It is more difficult to maintain as a liquid than other gases. Therefore, fluorine compounds with oxygen and halogens are more acceptable here.

Some of these compounds are not inferior in their oxidizing properties to liquid fluorine, but have a huge advantage; under normal conditions, these are either liquids or easily liquefied gases. Compare their properties by analyzing the data in table. 3.

Table 3

Connection name	Formula	Melting point, °C	Boiling point, °C	State of aggregation
Chlorine monofluoride	ClF	-155,6	-100,1	Gas
Chlorine trifluoride	СlF 3	-76,3	11,75	»
Bromine monofluoride	BrF	-33	20	Liquid
Bromine trifluoride	BrF 3	8,8	127,6	»
Bromine pentafluoride	BrF 5	-61,3	40,5	»
Iodine pentafluoride	IF 5	9,43	100,5	»
Iodine heptafluoride	IF 7	Vozg.	4,5	Gas
Fluorine oxide (oxygen diphtheria)	OF 2	-223,8	-144,8	»
Nitrogen trifluoride	NF 3	-208,5	-129,1	»
Perchloryl fluoride	FClO3	-146	-46,8	»
Fluorine	F 2	-227,6	-188,1	»

Among the fluorohaloid compounds, the most convenient for use in rocket fuel are chlorine trifluoride and bromine pentafluoride. It is known, for example, that back in 1956 in the USA, chlorine trifluoride was considered as a possible oxidizer for jet fuel. High chemical activity makes the use of such substances difficult. However, these difficulties are not absolute and can be overcome.

Further development of the chemistry of corrosion processes, the production of more corrosion-resistant materials, and advances in the synthesis of new fluorine-based oxidizers will likely make it possible to realize many of the plans of rocket scientists related to the use of element No. 9 and its compounds. But we won't make predictions. Modern technology is developing rapidly. Perhaps in a few years some fundamentally new types of engines will appear, and liquid-propellant rocket engines will fade into the realm of history... In any case, it is indisputable that fluorine has not yet said its last word in space exploration.

Prevalence

Each liter of sea water contains 0.3 mg of fluoride. There is 20 times more of it in oyster shells.

Coral reefs contain millions of tons of fluoride. The average fluorine content in living organisms is 200 times less than in the earth's crust.

What does fluoride look like?

Under normal conditions, fluorine is a pale yellow gas; at a temperature of -188°C it is a canary-yellow liquid; at -228°C fluorine freezes and turns into light yellow crystals. If the temperature is reduced to -252°C, these crystals will become discolored.

What does fluoride smell like?

The smells of chlorine, bromine and iodine, as you know, are difficult to classify as pleasant. In this respect, fluorine differs little from its fellow halogens. Its smell is sharp and irritating - reminiscent of both the smells of chlorine and ozone. One millionth of fluorine in the air is enough for the human nose to detect its presence.

In the valley of a thousand smokes

Gases of volcanic origin sometimes contain hydrogen fluoride. The most famous natural source of such gases is the fumaroles of the Valley of a Thousand Smokes (Alaska). Every year, about 200 thousand tons of hydrogen fluoride are carried into the atmosphere with volcanic smoke.

Davy testifies

“I undertook the experiment on the electrolysis of pure hydrofluoric acid with great interest, since it provided the most probable opportunity to verify the actual nature of fluorine. But significant difficulties were encountered in carrying out the process. Liquid hydrofluoric acid immediately destroyed glass and all animal and plant matter. It acts on all bodies containing metal oxides. I do not know of a single substance that would not dissolve in it, with the exception of certain metals, charcoal, phosphorus, sulfur and some chlorine compounds.”

Fluorine and nuclear energy

The role of fluorine and its compounds in the production of nuclear fuel is exceptional. We can safely say that without fluorine, there would still not be a single nuclear power plant in the world, and the total number of research reactors would not be difficult to count on one hand.

It is well known that not all uranium can serve as nuclear fuel, but only some of its isotopes, primarily 235 U.

It is not easy to separate isotopes that differ from one another only in the number of neutrons in the nucleus, and the heavier the element, the less the difference in weight is felt. The separation of uranium isotopes is further complicated by the fact that almost all modern separation methods are designed for gaseous substances or volatile liquids.

Uranium boils at about 3500°C. What materials would have to be used to make columns, centrifuges, and diaphragms for separating isotopes if we had to work with uranium vapor?! An exceptionally volatile compound of uranium is its hexafluoride UF 6. It boils at 56.2°C. Therefore, it is not uranium metal that is separated, but uranium-235 and uranium-238 hexafluorides. Naturally, these substances do not differ from each other in their chemical properties. The process of separating them takes place in rapidly rotating centrifuges.

Molecules of uranium hexafluoride, accelerated by centrifugal force, pass through finely porous partitions: “light” molecules containing 235 U pass through them a little faster than “heavy” ones.

After separation, uranium hexafluoride is converted into UF 4 tetrafluoride, and then into uranium metal.

Uranium hexafluoride is obtained as a result of the reaction between uranium and elemental fluorine, but this reaction is difficult to control. It is more convenient to treat uranium with fluorine compounds with other halogens, for example ClF 3, BrF and BrF 6. The production of uranium tetrafluoride UF 4 involves the use of hydrogen fluoride. It is known that in the mid-60s in the United States, almost 10% of all hydrogen fluoride was spent on uranium production - about 20 thousand tons.

The production processes of such important materials for nuclear technology as thorium, beryllium and zirconium also include phases of obtaining fluorine compounds of these elements.

Plastic platinum

Lion devouring the Sun. This symbol meant among alchemists the process of dissolving gold in aqua regia - a mixture of nitric and hydrochloric acids. All precious metals are chemically very stable. Gold does not dissolve in either acids (except selenic acid) or alkalis. And only aqua regia “devours” both gold and even platinum.

At the end of the 30s, a substance appeared in the arsenal of chemists against which even the “lion” was powerless. Aqua regia turned out to be too tough for plastic - fluoroplastic-4, also known as Teflon. Teflon molecules differ from polyethylene molecules in that all the hydrogen atoms surrounding the main chain (... - C - C - C - ...) are replaced by fluorine.

Fluoroplast-4 is produced by polymerization of tetrafluoroethylene, a colorless, non-toxic gas.

The polymerization of tetrafluoroethylene was discovered by accident. In 1938, the supply of this gas from a cylinder suddenly stopped in one of the foreign laboratories. When the cylinder was opened, it turned out that it was filled with an unknown white powder, which turned out to be polytetrafluoroethylene. The study of the new polymer showed its amazing chemical resistance and high electrical insulating properties. Now many important parts of aircraft, cars, and machine tools are pressed from this polymer.

Other polymers containing fluorine are also widely used. These are polytrifluorochloroethylene (fluoroplastic-3), polyvinyl fluoride, polyvinylidene fluoride. If at first polymers containing fluorine were only substitutes for other plastics and non-ferrous metals, now they themselves have become irreplaceable materials.

The most valuable properties of fluorine-containing plastics are their chemical and thermal stability, low specific gravity, low moisture permeability, excellent electrical insulation characteristics, and lack of brittleness even at very low temperatures. These properties have led to the widespread use of fluoroplastic in the chemical, aviation, electrical, nuclear, refrigeration, food and pharmaceutical industries, as well as in medicine.

Fluorine-containing rubbers are also considered very promising materials. Several types of rubber-like materials have already been created in different countries, the molecules of which include fluorine. True, none of them, in terms of their totality of properties, rises above other rubbers to the same extent as fluoroplastic-4 does above conventional plastics, but they have many valuable qualities. In particular, they are not destroyed by fuming nitric acid and do not lose elasticity over a wide temperature range

Some interesting facts from the history of chemistry
Discovery of halogens
Discovery of fluorine

The separation of fluorine gas from fluorine-containing substances has proven to be one of the most difficult experimental problems. Fluorine is exceptionally reactive; and often its interaction with other substances occurs with ignition and explosion.

The first victims of fluoride were two members of the Irish Academy of Sciences, brothers George and Thomas Knox. Thomas Knox died from hydrogen fluoride poisoning, and Georg became disabled. The next victim was the Belgian chemist P. Layet. The French chemist Jerome Nickles suffered martyrdom while conducting experiments on the isolation of fluorine. French chemists Joseph Gay-Lussac, Louis Tenard and English chemist Humphry Davy were poisoned by inhaling small amounts of hydrogen fluoride and also suffered serious burns. When trying to isolate fluorine using the electrolysis of its compounds, the French chemist Edmond Fremy and the English electrochemist Georg Gore caused damage to their health. Only in 1886 did the French chemist Henri Moissan manage to obtain fluorine relatively painlessly. Moissan accidentally discovered that during the electrolysis of a mixture of liquid anhydrous HF and potassium hydrodifluoride (KHF2) in a platinum vessel at the anode, a light yellow gas with a specific pungent odor is released. However, when Moissan reported to the Paris Academy of Sciences about his discovery, one of the scientist’s eyes was covered with a black bandage:

The Nobel Prize in Chemistry was awarded to Moissan in 1906 "in recognition of the large volume of research he produced the element fluorine and the introduction into laboratory and industrial practice of the electric furnace named after him."

Discovery of chlorine

The discoverer of chlorine was the Swedish pharmacist Carl Scheele, whose chemical intuition was truly amazing; according to the French chemist Jean Baptiste Dumas, Scheele “could not touch any body without making a discovery.” At the age of 32, he was awarded the title of member of the Stockholm Academy of Sciences, although he was only a pharmacist's assistant; in the same year he received a position as manager of a pharmacy owned by the widow Margarita Sonneman, who two days before Scheele's death became his wife.

This is how Scheele described his experiment, performed in 1774: “I placed a mixture of black magnesia with muric acid in a retort, to the neck of which I attached a bubble devoid of air, and placed it in a sand bath. The bubble was filled with gas, which colored it yellow: The gas had a yellow-green color and a piercing odor:

The modern designation for this reaction is: MnO2 + 4HCl = Cl2 + MnCl2 + 2H2O.

In 1812, the French chemist Gay-Lussac gave this gas its modern name - chlorine, which means yellow-green in Greek.

Discovery of bromine

Bromine was discovered by twenty-four-year-old laboratory assistant Antoine-Jerome Balard. Balard studied the mother brines of the southern salt marshes of France. During one of his experiments, when he exposed brine to chlorine, he noticed the appearance of a very intense yellow color caused by the reaction of the sodium bromide contained in the solution with chlorine. After several years of hard work, Balar isolated the required amount of dark brown liquid, which he called murid. At the Paris Academy of Sciences, Gay-Lussac and Tenard confirmed Balard's discovery of a new simple substance, but found the name unsuccessful and proposed their own - "bromine", which translated from Greek meant fetid.

Subsequently, the French chemist Charles Gerard, who did not receive the chair of chemistry at the French College, which was transferred to Balard, highly appreciating his discovery of bromine, could not resist a sharp exclamation: “It was not Balard who discovered bromine, but bromine that was discovered by Balard!”

Discovery of iodine

In 1811, the French chemist-technologist and pharmacist Bernard Courtois discovered iodine. His friends tell interesting details of this discovery. Courtois had a favorite cat, who usually sat on his owner’s shoulder during lunch. Courtois often ate lunch in the laboratory. One day during lunch, the cat, frightened by something, jumped onto the floor, but ended up on bottles standing near the laboratory table. In one bottle Courtois prepared for the experiment a suspension of algae ash (containing sodium iodide) in ethanol, and in the other there was concentrated sulfuric acid. The bottles broke and the liquids mixed. Clouds of blue-violet steam began to rise from the floor, which settled on surrounding objects in the form of tiny black-violet crystals with a metallic sheen and a pungent odor. This was the new chemical element iodine.

(Facts taken from the following books: M. Jua. History of chemistry. 1975; B. D. Stepin, L. Yu. Alikberova. A book on chemistry for home reading. 1995. K. Manolov. Great chemists. (vol. 1, vol. 2), 1976).