The most amazing substances. Chemical records What are the two lightest chemical elements

We present a selection of chemical records from the Guinness Book of Records.
Due to the fact that new substances are constantly being discovered, this collection is not permanent.

Chemical records for inorganic substances

• The most abundant element in the earth's crust is oxygen O. Its weight content is 49% of the mass of the earth's crust.
• The rarest element in the earth's crust is astatine At. Its content in the entire earth's crust is only 0.16 grams. The second most rare is Francium Fr.
• The most abundant element in the universe is hydrogen H. Approximately 90% of all atoms in the universe are hydrogen. The second most common in the universe is helium He.
• The strongest stable oxidizing agent is a complex of krypton difluoride and antimony pentafluoride. Due to its strong oxidizing effect (it oxidizes almost all elements to the highest oxidation states, including oxygen in the air), it is very difficult for it to measure the electrode potential. The only solvent that reacts with it slowly enough is anhydrous hydrogen fluoride.
• The densest substance on planet Earth is osmium. The density of osmium is 22.587 g / cm 3.
• The lightest metal is lithium Li. The density of lithium is 0.543 g / cm 3.
• The densest compound is divungsten carbide W 2 C. The density of divungsten carbide is 17.3 g / cm 3.
• At present, graphene aerogels are the solids with the lowest density. They are a system of graphene and nanotubes filled with air spaces. The lightest of these aerogels has a density of 0.00016 g / cm 3. The previous lowest density solid is silicon airgel (0.005 g / cm 3). Silicon airgel is used to collect micrometeorites present in comet tails.
• The lightest gas and, at the same time, the lightest non-metal is hydrogen. The mass of 1 liter of hydrogen is only 0.08988 g. In addition, hydrogen is also the most low-melting non-metal at normal pressure (melting point is -259.19 0 С).
• The lightest liquid is liquid hydrogen. The mass of 1 liter of liquid hydrogen is only 70 grams.
• The heaviest inorganic gas at room temperature is tungsten hexafluoride WF 6 (boiling point is +17 0 C). The density of tungsten hexafluoride as a gas is 12.9 g / l. Among gases with a boiling point below 0 ° C, the record is held by tellurium hexafluoride TeF 6 with a gas density at 25 ° C of 9.9 g / l.
• The most expensive metal in the world is Californian Cf. The price of 1 gram of 252 Cf isotope reaches 500 thousand US dollars.
• Helium He is the substance with the lowest boiling point. Its boiling point is -269 0 С. Helium is the only substance that does not have a melting point at ordinary pressure. Even at absolute zero, it remains liquid and can only be obtained in solid form under pressure (3 MPa).
• The most refractory metal and the substance with the highest boiling point is tungsten W. The melting point of tungsten is +3420 0 С, and the boiling point is +5680 0 С.
• The most refractory material is an alloy of hafnium and tantalum carbides (1: 1) (melting point +4215 0 С)
• The most low-melting metal is mercury. The melting point of mercury is -38.87 0 С. Mercury is also the heaviest liquid, its density at 25 ° C is 13.536 g / cm 3.
• The most acid-resistant metal is iridium. Until now, no acids or mixtures thereof are known in which iridium would dissolve. However, it can be dissolved in alkalis with oxidizing agents.
• The strongest stable acid is a solution of antimony pentafluoride in hydrogen fluoride.
• The hardest metal is chromium Cr.
• The softest metal at 25 ° C is cesium.
• The hardest material is still diamond, although there are already about a dozen substances approaching it in hardness (boron carbide and nitride, titanium nitride, etc.).
• The most conductive metal at room temperature is silver Ag.
• The lowest speed of sound in liquid helium is at 2.18 K, it is only 3.4 m / s.
• The highest speed of sound in a diamond is 18,600 m / s.
• The isotope with the shortest half-life is Li-5, which decays in 4.4 · 10-22 seconds (proton burst). Due to such a short life span, not all scientists recognize the fact of its existence.
• The isotope with the longest measured half-life is Te-128, with a half-life of 2.2 × 1024 years (beta double decay).
• Xenon and cesium have the most stable isotopes (36 each).
• Boron and iodine have the shortest names for a chemical element (3 letters each).
• The longest names of the chemical element (eleven letters each) have protactinium Pa, rutherfordium Rf, darmstadtium Ds.

Chemical records for organic matter

• The heaviest organic gas at room temperature and the heaviest gas among all at room temperature is N- (octafluorobut-1-ylidene) -O-trifluoromethylhydroxylamine (bp +16 C). Its density as a gas is 12.9 g / l. Among gases with a boiling point below 0 ° C, the record is held by perfluorobutane with a gas density at 0 ° C of 10.6 g / l.
• The most bitter substance is denatonium saccharinate. The combination of denatonium benzoate with sodium saccharin gave the substance 5 times more bitter than the previous record holder (denatonium benzoate).
• The most non-toxic organic matter is methane. With an increase in its concentration, intoxication occurs due to a lack of oxygen, and not as a result of poisoning.
• The strongest adsorbent for water, was obtained in 1974 from a starch derivative, acrylamide and acrylic acid. This substance is able to hold water, the mass of which is 1300 times its own.
• The strongest adsorbent for petroleum products is carbon airgel. 3.5 kg of this substance can absorb 1 ton of oil.
• The most offensive compounds are ethylselenol and butyl mercaptan - their smell resembles a combination of the smells of rotting cabbage, garlic, onions and sewage at the same time.
• The sweetest substance is N - ((2,3-methylenedioxyphenylmethylamino) - (4-cyanophenylimino) methyl) aminoacetic acid (lugduname). This substance is 205,000 times more sweet than a 2% sucrose solution. There are several analogues with similar sweetness. The sweetest industrial substance is talin (a complex of thaumatin and aluminum salts), which is 3,500 - 6,000 times sweeter than sucrose. Recently, neotame has appeared in the food industry with a sweetness 7000 times higher than sucrose.
• The slowest enzyme is nitrogenase, which catalyzes the assimilation of atmospheric nitrogen by nodule bacteria. The complete cycle of conversion of one nitrogen molecule into 2 ammonium ions takes one and a half seconds.
• The organic substance with the highest nitrogen content is either bis (diazotetrazolyl) hydrazine C2H2N12, containing 86.6% nitrogen, or tetraazidomethane C (N3) 4, containing 93.3% nitrogen (depending on whether the latter is considered organic or not) ... They are explosives that are extremely sensitive to shock, friction and heat. Of inorganic substances, the record belongs of course to gaseous nitrogen, and from compounds - to hydrazoic acid HN 3.
• The longest chemical name has 1578 characters in English and is a modified nucleotide sequence. This substance is called: Adenosene. N - 2′-O- (tetrahydromethoxypyranyl) adenylyl- (3 '→ 5 ′) - 4-deamino-4- (2,4-dimethylphenoxy) -2′-O- (tetrahydromethoxypyranyl) cytidylyl- (3' → 5 ′) -4-deamino-4- (2,4-dimethylphenoxy) -2′-O- (tetrahydromethoxypyranyl) cytidylyl- (3 '→ 5 ′) - N - 2′-O- (tetrahydromethoxypyranyl) cytidylyl- (3 '→ 5 ′) - N - 2′-O- (tetrahydromethoxypyranyl) cytidylyl- (3' → 5 ′) - N - 2′-O- (tetrahydromethoxypyranyl) guanylyl- (3 '→ 5 ′) - N- -2′-O- (tetrahydromethoxypyranyl) guanylyl- (3 '→ 5 ′) - N - 2′-O- (tetrahydromethoxypyranyl) adenylyl- (3' → 5 ′) - N - 2′-O- (tetrahydromethoxypyranyl ) cytidylyl- (3 '→ 5 ′) - 4-deamino-4- (2,4-dimethylphenoxy) -2′-O- (tetrahydromethoxypyranyl) cytidylyl- (3' → 5 ′) - 4-deamino-4- ( 2,4-dimethylphenoxy) -2′-O- (tetrahydromethoxypyranyl) cytidylyl- (3 '→ 5 ′) - N - 2′-O- (tetrahydromethoxypyranyl) guanylyl- (3' → 5 ′) - 4-deamino- 4- (2,4-dimethylphenoxy) -2′-O- (tetrahydromethoxypyranyl) cytidylyl- (3 '→ 5 ′) - N - 2′-O- (tetrahydromethoxypyranyl) cytidylyl- (3' → 5 ′) - N --2′-O- (tetrahydromethoxypyranyl) cytidylyl- (3 '→ 5 ′) - N - 2′-O- (tetrahydromethoxypyranyl) adenylyl- (3' → 5 ′) - N - 2′-O- ( tetrahydro methoxypyranyl) cytidylyl- (3 '→ 5 ′) - N - 2′-O- (tetrahydromethoxypyranyl) cytidylyl- (3' → 5 ′) - N - 2 ′, 3′-O- (methoxymetylene) -octadecakis ( 2-chlorophenyl) ester. five'-.
• The longest chemical name is DNA isolated from human mitochondria and consists of 16569 base pairs. The full name of this compound contains about 207,000 characters.
• The system of the largest number of immiscible liquids, again stratifying into components after mixing, contains 5 liquids: mineral oil, silicone oil, water, benzyl alcohol and N-perfluoroethyl perfluoropyridine.
• The densest organic liquid at room temperature is diiodomethane. Its density is 3.3 g / cm3.
• The most refractory individual organic substances are some aromatic compounds. Of the condensed ones, this is tetrabenzheptacene (melting point +570 C), and of the non-condensed ones, it is p-septyphenyl (melting point +545 C). There are organic compounds for which the melting point is not measured precisely, for example, for hexabenzocoronene it is indicated that its melting point is higher than 700 C. The product of temperature crosslinking of polyacrylonitrile decomposes at a temperature of about 1000 C.
• The organic substance with the highest boiling point is hexatriaconylcyclohexane. It boils at + 551 ° C.
• The longest alkane is C390H782 nonacontatricthane. It was specially synthesized to study the crystallization of polyethylene.
• The longest protein is the muscle protein titin. Its length depends on the type of living organism and localization. Mouse titin, for example, has 35,213 amino acid residues (molecular weight 3,906,488 Da), human titin has a length of up to 33,423 amino acid residues (molecular weight 3,713,712 Da).
• The longest genome is the genome of the plant Paris japonica. It contains 150,000,000,000 base pairs - 50 times that of humans (3,200,000,000 base pairs).
• The largest molecule is the DNA of the first human chromosome. It contains about 10,000,000,000 atoms.
• The individual explosive with the highest detonation rate is 4,4'-dinitroazofuroxan. Its measured detonation velocity was 9700 m / s. According to unverified data, ethyl perchlorate has an even higher detonation rate.
• The individual explosive with the highest heat of explosion is ethylene glycol dinitrate. Its heat of explosion is 6606 kJ / kg.
• The strongest organic acid is pentacyanocyclopentadiene.
• The strongest base is possibly 2-methylcyclopropenyllithium. The strongest non-ionic base is phosphazene, a rather complex structure.

The universe hides many secrets in its depths. For a long time, people have tried to unravel as many of them as possible, and, despite the fact that this is not always possible, science is moving forward by leaps and bounds, allowing us to learn more and more about our origins. So, for example, many will be interested in what is the most common in the Universe. Most people will immediately think of water, and they will be partly right, because the most common element is hydrogen.

The most abundant element in the universe

It is extremely rare that people have to deal with pure hydrogen. However, in nature, it is very often found in connection with other elements. For example, by reacting with oxygen, hydrogen turns into water. And this is far from the only compound that contains this element, it is found everywhere, not only on our planet, but also in space.

How the Earth appeared

Many millions of years ago, hydrogen, without exaggeration, became a building material for the entire Universe. After all, after the big bang, which became the first stage in the creation of the world, nothing existed except this element. elementary, since it consists of only one atom. Over time, the most abundant element in the universe began to form clouds, which later became stars. And already inside them, reactions took place, as a result of which new, more complex elements appeared that gave birth to planets.

Hydrogen

This element accounts for about 92% of the atoms in the universe. But it is found not only in the composition of stars, interstellar gas, but also common elements on our planet. Most often it exists in a bound form, and the most common compound is, of course, water.

In addition, hydrogen is part of a number of carbon compounds that form oil and natural gas.

Output

Despite the fact that it is the most common element in the whole world, surprisingly, it can be dangerous to humans, because it sometimes ignites when it reacts with air. To understand how important hydrogen played in the creation of the Universe, it is enough to realize that without it nothing living on Earth would have appeared.

A chemical element is a collective term describing a set of atoms of a simple substance, that is, one that cannot be divided into any simpler (in terms of the structure of their molecules) constituents. Imagine receiving a piece of pure iron and asking you to break it down into hypothetical constituents using any device or method chemists have ever invented. However, there is nothing you can do, the iron will never split into something simpler. A simple substance - iron - corresponds to the chemical element Fe.

Theoretical definition

The experimental fact noted above can be explained using the following definition: a chemical element is an abstract set of atoms (not molecules!) Of the corresponding simple substance, i.e., atoms of the same type. If there was a way to look at each of the individual atoms in the piece of pure iron mentioned above, then they would all be the same - iron atoms. In contrast, a chemical compound such as iron oxide always contains at least two different kinds of atoms: iron atoms and oxygen atoms.

Terms you should know

Atomic mass: the mass of protons, neutrons, and electrons that make up an atom of a chemical element.

Atomic number: the number of protons in the nucleus of an atom of an element.

Chemical symbol: a letter or a pair of latin letters representing the designation of this element.

Chemical compound: a substance that consists of two or more chemical elements combined with each other in a certain proportion.

Metal: an element that loses electrons in chemical reactions with other elements.

Metalloid: an element that reacts sometimes as a metal and sometimes as a non-metal.

Non-metal: an element that seeks to obtain electrons in chemical reactions with other elements.

Periodic table of chemical elements: a system for classifying chemical elements according to their atomic numbers.

Synthetic element: one that is obtained artificially in a laboratory and, as a rule, does not occur in nature.

Natural and synthetic elements

Ninety-two chemical elements are found naturally on Earth. The rest were obtained artificially in laboratories. A synthetic chemical element is typically the product of nuclear reactions in particle accelerators (devices used to increase the speed of subatomic particles such as electrons and protons) or nuclear reactors (devices used to control the energy released in nuclear reactions). The first synthetic element obtained with atomic number 43 was technetium, discovered in 1937 by the Italian physicists C. Perrier and E. Segre. Apart from technetium and promethium, all synthetic elements have nuclei larger than those of uranium. The last synthetic chemical element to get its name is livermorium (116), and before it was flerovium (114).

Two dozen common and important elements

* If no value is specified, the item is less than 0.1 percent.

The Big Bang as the Root Cause of Matter Formation

What was the very first chemical element in the universe? Scientists believe the answer to this question lies in the stars and in the processes by which stars are formed. The universe is believed to have originated at some point in time between 12 and 15 billion years ago. Until this moment, nothing that exists, except energy, is not thought of. But something happened that turned this energy into a huge explosion (called the Big Bang). In the seconds after the Big Bang, matter began to form.

The first simplest forms of matter to appear were protons and electrons. Some of them combine to form hydrogen atoms. The latter consists of one proton and one electron; it is the simplest atom that can exist.

Slowly, over long periods of time, hydrogen atoms began to clump together in specific regions of space, forming dense clouds. The hydrogen in these clouds was pulled into compact formations by gravitational forces. Eventually, these clouds of hydrogen became dense enough to form stars.

Stars as chemical reactors of new elements

A star is simply a mass of matter that generates the energy of nuclear reactions. The most common of these reactions is a combination of four hydrogen atoms to form one helium atom. Once stars began to form, helium became the second element to appear in the universe.

As stars get older, they shift from hydrogen-helium nuclear reactions to other types of nuclear reactions. In them, helium atoms form carbon atoms. Later, carbon atoms form oxygen, neon, sodium and magnesium. Later still, neon and oxygen combine with each other to form magnesium. As these reactions continue, more and more chemical elements are formed.

The first systems of chemical elements

Over 200 years ago, chemists began looking for ways to classify them. In the middle of the nineteenth century, about 50 chemical elements were known. One of the questions that chemists have sought to resolve. boiled down to the following: a chemical element is a substance completely different from any other element? Or are some elements related to others in some way? Is there a common law uniting them?

Chemists have proposed various systems of chemical elements. So, for example, the English chemist William Prout in 1815 suggested that the atomic masses of all elements are multiples of the mass of the hydrogen atom, if we take it equal to unity, that is, they must be whole numbers. At that time, the atomic masses of many elements had already been calculated by J. Dalton in relation to the mass of hydrogen. However, if for carbon, nitrogen, oxygen this is approximately the case, then chlorine with a mass of 35.5 did not fit into this scheme in any way.

German chemist Johann Wolfgang Dobereiner (1780 - 1849) showed in 1829 that three elements from the so-called group of halogens (chlorine, bromine and iodine) can be classified according to their relative atomic masses. The atomic weight of bromine (79.9) turned out to be almost exactly the average of the atomic weights of chlorine (35.5) and iodine (127), namely 35.5 + 127 ÷ 2 = 81.25 (close to 79.9). This was the first approach to the construction of one of the groups of chemical elements. Dobereiner discovered two more such triads of elements, but he failed to formulate a general periodic law.

How the periodic table of chemical elements appeared

Most of the early classification schemes were not very successful. Then, around 1869, almost one discovery was made by two chemists, and at almost the same time. Russian chemist Dmitry Mendeleev (1834-1907) and German chemist Julius Lothar Meyer (1830-1895) proposed organizing elements that have similar physical and chemical properties into an ordered system of groups, rows and periods. At the same time, Mendeleev and Meyer pointed out that the properties of chemical elements are periodically repeated depending on their atomic weights.

Today Mendeleev is generally considered to be the discoverer of the periodic law because he took one step that Meyer did not. When all the elements were located in the periodic table, some gaps appeared in it. Mendeleev predicted that these are places for elements that have not yet been discovered.

However, he went even further. Mendeleev predicted the properties of these as yet undiscovered elements. He knew where they were on the periodic table, so he could predict their properties. It is noteworthy that every predicted chemical element by Mendeleev, the future gallium, scandium and germanium, were discovered less than ten years after he published the periodic law.

Short form of the periodic table

There have been attempts to calculate how many versions of the graphic representation of the periodic table were proposed by different scientists. It turned out more than 500. Moreover, 80% of the total number of options are tables, and the rest are geometric shapes, mathematical curves, etc. As a result, four types of tables have found practical application: short, semi-long, long and staircase (pyramidal). The latter was proposed by the great physicist N. Bohr.

The figure below shows the short form.

In it, chemical elements are arranged in ascending order of their atomic numbers from left to right and from top to bottom. So, the first chemical element of the periodic table hydrogen has atomic number 1 because the nucleus of hydrogen atoms contains one and only one proton. Likewise, oxygen has an atomic number of 8, since the nuclei of all oxygen atoms contain 8 protons (see figure below).

The main structural fragments of the periodic table are periods and groups of elements. In six periods, all cells are filled, the seventh is not yet completed (although elements 113, 115, 117 and 118 have been synthesized in laboratories, they have not yet been officially registered and have no names).

Groups are subdivided into main (A) and secondary (B) subgroups. Elements of the first three periods, each containing one row-row, are included exclusively in A-subgroups. The other four periods include two row-rows.

Chemical elements in the same group tend to have similar chemical properties. So, the first group is made up of alkali metals, the second - alkaline earth metals. Elements located in the same period have properties slowly changing from an alkali metal to a noble gas. The figure below shows how one of the properties - the atomic radius - changes for individual elements in the table.

Long-period form of the periodic table

It is shown in the figure below and is divided in two directions, row and column. There are seven period lines, as in the short form, and 18 columns called groups or families. In fact, the increase in the number of groups from 8 in the short form to 18 in the long one is obtained by placing all the elements in the periods starting from the 4th, not in two, but in one line.

Two different numbering systems are used for groups, as shown at the top of the table. The Roman numeral system (IA, IIA, IIB, IVB, etc.) has traditionally been popular in the United States. Another system (1, 2, 3, 4, etc.) is traditionally used in Europe and was recommended for use in the United States a few years ago.

The look of the periodic tables in the figures above is a bit misleading, as in any such published table. The reason for this is that the two groups of items shown at the bottom of the tables should actually be located within them. Lanthanides, for example, belong to period 6 between barium (56) and hafnium (72). In addition, actinides belong to period 7 between radium (88) and rutherfordium (104). If they were inserted into a table, it would become too wide to fit on a piece of paper or a wall chart. Therefore, it is customary to place these elements at the bottom of the table.

The most common

Lithosphere. Oxygen (O), 46.60% by weight. Discovered in 1771 by Karl Scheele (Sweden).
Atmosphere. Nitrogen (N), 78.09% by volume, 75.52% by weight. Discovered in 1772 by Rutherford (Great Britain).
Universe. Hydrogen (H), 90% of the total substance. Discovered in 1776 by Henry Cavendish (Great Britain).

The rarest (out of 94)

Lithosphere.
Astatine (At): 0.16 g in the earth's crust. Discovered in 1940 by Corson (USA) with collaborators. The naturally occurring isotope astatine 215 (215At) (discovered in 1943 by B. Karlik and T. Bernert, Austria) exists in an amount of only 4.5 nanograms.
Atmosphere.
Radon (Rn): only 2.4 kg (6 · 10–20 volume of one part per 1 million). Opened in 1900 by Dornom (Germany). The concentration of this radioactive gas in areas of granite deposits is believed to be the cause of a number of cancers. The total mass of radon in the earth's crust, from which atmospheric gas reserves are replenished, is 160 tons.

The easiest

Gas:
Hydrogen (H) has a density of 0.00008989 g / cm3 at a temperature of 0 ° C and a pressure of 1 atm. Discovered in 1776 by Cavendish (Great Britain).
Metal.
Lithium (Li), with a density of 0.5334 g / cm3, is the lightest of all solids. Discovered in 1817 by Arfvedson (Sweden).

Maximum density

Osmium (Os), with a density of 22.59 g / cm3, is the heaviest of all solids. Opened in 1804 by Tennant (Great Britain).

Heaviest gas

It is radon (Rn), the density of which is 0.01005 g / cm3 at 0 ° C. Opened in 1900 by Dornom (Germany).

Last received

Element 108, or unniloktia (Uno). This provisional name was given by the International Union of Pure and Applied Chemistry (IUPAC). Obtained in April 1984 by G. Münzenberg and colleagues (West Germany), who observed only 3 atoms of this element in the laboratory of the Society for Heavy Ion Research in Darmstadt. In June of the same year, it was reported that this element had also been received by Yu.Ts. Oganesyan with colleagues at the Joint Institute for Nuclear Research, Dubna, USSR.

A single unification atom (Une) was produced by bombarding bismuth with iron ions in the laboratory of the Heavy Ion Research Society, Darmstadt, West Germany, August 29, 1982. It has the largest ordinal number (element 109) and the largest atomic mass (266) ... According to the most preliminary data, Soviet scientists observed the formation of an isotope of element 110 with an atomic mass of 272 (tentatively called ununnilium (Uun)).

The cleanest

Helium-4 (4He), obtained in April 1978 by P.V. McLintock of Lancaster University, USA, has less than 2 parts of impurities per 1015 parts of volume.

The hardest

Carbon (C). In allotropic form, diamond has a hardness according to the Knoop method - 8400. It has been known since prehistoric times.

The most expensive

California (Cf) was selling at $ 10 per microgram in 1970. Opened in 1950 by Seaborg (USA) with employees.

The most flexible

Gold (Au). From 1 g, you can pull out a wire 2.4 km long. Known since 3000 BC.

Highest tensile strength

Boron (V) - 5.7 GPa. Opened in 1808 by Gay-Lussac and Thénard (France) and H. Davy (Great Britain).

Melting point / boiling point

Lowest.
Among non-metals, helium-4 (4He) has the lowest melting point –272.375 ° С at a pressure of 24.985 atm and the lowest boiling point –268.928 ° С. Helium was discovered in 1868 by Lockyer (Great Britain) and Jansen (France). Monatomic hydrogen (H) must be a non-liquefiable superfluid gas. Among metals, the corresponding parameters for mercury (Hg) are –38.836 ° С (melting point) and 356.661 ° С (boiling point).
The tallest.
Among non-metals, the highest melting point and boiling point is for carbon (C) known from prehistoric times: 530 ° C and 3870 ° C. However, it seems controversial that graphite is stable at high temperatures. Passing at 3720 ° C from a solid to a vapor state, graphite can be obtained as a liquid at a pressure of 100 atm and a temperature of 4730 ° C. Among metals, the corresponding parameters for tungsten (W) are 3420 ° C (melting point) and 5860 ° C (boiling point). Discovered in 1783 by H.H. and F. d ​​"Eluyaram (Spain).

Isotopes

Most isotopes(36 each) for xenon (Xe), discovered in 1898 by Ramsay and Travers (Great Britain), and for cesium (Cs), discovered in 1860 by Bunsen and Kirchhoff (Germany). The smallest amount (3: protium, deuterium and tritium) in hydrogen (H) was discovered in 1776 by Cavendish (Great Britain).

The most stable

Tellurium-128 (128Te), according to double beta decay data, has a half-life of 1.5 × 1024 years. Tellur (Te) was discovered in 1782 by Müller von Reichenstein (Austria). The isotope 128Те was first discovered in its natural state in 1924 by F. Aston (Great Britain). The data on its superstability were again confirmed in 1968 by the studies of E. Alexander Jr., B. Srinivasan and O. Manuel (USA). The alpha decay record belongs to samarium-148 (148Sm) - 8 1015 years. The record for beta decay belongs to the isotope of cadmium 113 (113Cd) - 9 × 1015 years. Both isotopes were discovered in their natural state by F. Aston, respectively, in 1933 and 1924. The radioactivity of 148Sm was discovered by T. Wilkins and A. Dempster (USA) in 1938, and the radioactivity of 113Cd in 1961 was discovered by D. Watt and R. Glover (Great Britain).

Most unstable

The lifetime of lithium-5 (5Li) is limited to 4.4 · 10–22 s. The isotope was first discovered by E. Titterton (Australia) and T. Brinkley (Great Britain) in 1950.

The most poisonous

Among non-radioactive substances, the most stringent restrictions are established for beryllium (Be) - the maximum permissible concentration (MPC) of this element in the air is only 2 μg / m3. Among the radioactive isotopes existing in nature or produced by nuclear facilities, the most stringent restrictions on the content in the air are established for thorium-228 (228Th), which was first discovered by Otto Hahn (Germany) in 1905 (2.4 · 10-16 g / m3), and in terms of content in water - for radium-228 (228Ra), discovered by O. Gahn in 1907 (1.1 · 10-13 g / l). Ecologically, they have significant half-lives (i.e. over 6 months).

We all know that hydrogen fills our Universe by 75%. But do you know what other chemical elements there are that are no less important for our existence and play a significant role in the life of people, animals, plants and our entire Earth? Elements from this ranking shape our entire universe!

10. Sulfur (prevalence relative to silicon - 0.38)

This chemical element is listed under the symbol S in the periodic table and is characterized by atomic number 16. Sulfur is very natural.

9. Iron (prevalence relative to silicon - 0.6)

It is designated by the symbol Fe, atomic number - 26. Iron is very often found in nature, it plays an especially important role in the formation of the inner and outer shell of the Earth's core.

8. Magnesium (prevalence relative to silicon - 0.91)

In the periodic table, magnesium can be found under the symbol Mg, and its atomic number is 12. What is most surprising about this chemical element is that it is most often released when stars explode in the process of their transformation into supernova bodies.

7. Silicon (prevalence relative to silicon - 1)

Designated as Si. The atomic number of silicon is 14. This gray-blue metalloid is very rarely found in the earth's crust in its pure form, but it is quite common in other substances. For example, it can even be found in plants.

6. Carbon (prevalence relative to silicon - 3.5)

Carbon in Mendeleev's table of chemical elements is listed under the symbol C, its atomic number is 6. The most famous allotropic modification of carbon is one of the most coveted precious stones in the world - diamonds. Carbon is actively used in other industrial purposes for more everyday purposes.

5. Nitrogen (abundance relative to silicon - 6.6)

Symbol N, atomic number 7. First discovered by Scottish physician Daniel Rutherford, nitrogen is most commonly found in the form of nitric acid and nitrates.

4. Neon (abundance relative to silicon - 8.6)

It is designated by the symbol Ne, atomic number - 10. It is no secret that this particular chemical element is associated with a beautiful glow.

3. Oxygen (prevalence relative to silicon - 22)

A chemical element under the symbol O and with atomic number 8, oxygen is indispensable for our existence! But this does not mean that it is present only on Earth and serves only for human lungs. The universe is full of surprises.

2. Helium (abundance relative to silicon - 3.100)

The symbol for helium is He, the atomic number is 2. It is colorless, odorless and tasteless, non-toxic, and its boiling point is the lowest among all chemical elements. And thanks to him, the balls soar up!

1. Hydrogen (abundance relative to silicon - 40,000)

True number one on our list, hydrogen is in the periodic table under the symbol H and has atomic number 1. It is the lightest chemical element in the periodic table and the most abundant element in the entire studied universe.