What is the most abundant element in the Universe? Records in science and technology. Elements Terms you should know

A chemical element is a collective term that describes a collection of atoms of a simple substance, that is, one that cannot be divided into any simpler (according to the structure of their molecules) components. Imagine being given a piece of pure iron and being asked to separate it into its hypothetical constituents using any device or method ever invented by chemists. However, you can't do anything; the iron will never be divided 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 collection 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 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 element's atom.

Chemical symbol: a letter or pair of Latin letters representing the designation of a given 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 gain 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 produced artificially in a laboratory and is generally not found in nature.

Natural and synthetic elements

Ninety-two chemical elements occur 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 by nuclear reactions). The first synthetic element with atomic number 43 was technetium, discovered in 1937 by Italian physicists C. Perrier and E. Segre. Apart from technetium and promethium, all synthetic elements have nuclei larger than uranium. The last synthetic chemical element to receive its name is livermorium (116), and before it was flerovium (114).

Two dozen common and important elements

* If the value is not specified, then the element is less than 0.1 percent.

The Big Bang as the root cause of matter formation

What chemical element was the very first in the Universe? Scientists believe the answer to this question lies in stars and the processes by which stars are formed. The universe is believed to have come into being at some point in time between 12 and 15 billion years ago. Until this moment, nothing existing except energy is thought of. But something happened that turned this energy into a huge explosion (the so-called Big Bang). In the next 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 cluster together in certain areas of space, forming dense clouds. The hydrogen in these clouds was pulled together 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 energy from nuclear reactions. The most common of these reactions involves the combination of four hydrogen atoms forming one helium atom. Once stars began to form, helium became the second element to appear in the Universe.

As stars get older, they switch from hydrogen-helium nuclear reactions to other types. 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

More than 200 years ago, chemists began to look for ways to classify them. In the mid-nineteenth century, about 50 chemical elements were known. One of the questions that chemists sought to resolve. boiled down to the following: is a chemical element a substance completely different from any other element? Or some elements related to others in some way? Is there a general law that unites them?

Chemists proposed various systems of chemical elements. 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, i.e. they must be integers. 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 this is approximately the case for carbon, nitrogen, and oxygen, then chlorine with a mass of 35.5 did not fit into this scheme.

The German chemist Johann Wolfgang Dobereiner (1780 – 1849) showed in 1829 that three elements from the so-called halogen group (chlorine, bromine and iodine) could 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 constructing one of the groups of chemical elements. Dobereiner discovered two more such triads of elements, but he was unable to formulate a general periodic law.

How did the periodic table of chemical elements appear?

Most of the early classification schemes were not very successful. Then, around 1869, almost the same discovery was made by two chemists at almost the same time. Russian chemist Dmitri 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, series, and periods. At the same time, Mendeleev and Meyer pointed out that the properties of chemical elements periodically repeat depending on their atomic weights.

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

However, he went even further. Mendeleev predicted the properties of these not yet discovered elements. He knew where they were located on the periodic table, so he could predict their properties. Remarkably, every chemical element Mendeleev predicted, gallium, scandium, and germanium, was discovered less than ten years after he published his periodic law.

Short form of the periodic table

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

The picture 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. Thus, the first chemical element of the periodic table, hydrogen, has atomic number 1 because the nuclei of hydrogen atoms contain one and only one proton. Likewise, oxygen has atomic number 8 since the nuclei of all oxygen atoms contain 8 protons (see figure below).

The main structural fragments of the periodic system are periods and groups of elements. In six periods, all cells are filled, the seventh is not yet completed (elements 113, 115, 117 and 118, although synthesized in laboratories, have not yet been officially registered and do not have names).

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

Chemical elements in the same group tend to have similar chemical properties. Thus, the first group consists of alkali metals, the second - alkaline earth metals. Elements in the same period have properties that slowly change from an alkali metal to a noble gas. The figure below shows how one of the properties, 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, by rows and by columns. There are seven period rows, 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 form is obtained by placing all the elements in 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 USA several years ago.

The appearance of the periodic tables in the figures above is a little misleading, as with any such published table. The reason for this is that the two groups of elements shown at the bottom of the tables should actually be located within them. The lanthanides, for example, belong to period 6 between barium (56) and hafnium (72). Additionally, 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.

There are 94 chemical elements found in nature. To date, another 15 transuranium elements have been artificially obtained (elements from 95 to 109), the existence of 10 of them is indisputable.

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 mass. Discovered in 1772 by Rutherford (Great Britain).

Universe. Hydrogen (H), 90% of the total substance. Discovered in 1776 by Henry Cavendish (Great Britain).

Rarest (out of 94)

Lithosphere. Astatine (At): 0.16 g in the earth's crust. Opened in 1940 by Corson (USA) and employees. The naturally occurring isotope astatine 215 (215 At) (discovered in 1943 by B. Karlik and T. Bernert, Austria) exists in quantities 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 Dorn (Germany). The concentration of this radioactive gas in areas of granite rock deposits is believed to have caused a number of cancers. The total mass of radon found 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/cm 3 at a temperature of 0°C and a pressure of 1 atm. Opened in 1776 by Cavendish (Great Britain).

Metal. Lithium (Li), with a density of 0.5334 g/cm 3, is the lightest of all solids. Discovered in 1817 by Arfvedson (Sweden).

Maximum Density

Osmium (Os), with a density of 22.59 g/cm 3, is the heaviest of all solids. Discovered in 1804 by Tennant (Great Britain).

Heaviest gas

It is radon (Rn), the density of which is 0.01005 g/cm 3 at 0°C. Opened in 1900 by Dorn (Germany).

Last received

Element 108, or unniloctium (Uno). This provisional name is given by the International Union of Pure and Applied Chemistry (IUPAC). Obtained in April 1984 by G. Münzenberg and co-workers (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, a message appeared that this element was also obtained by Yu.Ts. Oganesyan and collaborators at the Joint Institute for Nuclear Research, Dubna, USSR.

A single unnilenium atom (Une) was obtained by bombarding bismuth with iron ions in the laboratory of the Heavy Ion Research Society, Darmstadt, West Germany, on August 29, 1982. It has the highest atomic number (element 109) and the highest 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 (preliminary name - ununnilium (Uun)).

The cleanest

Helium-4 (4 He), obtained in April 1978 by P.V. McLintock of Lancaster University, USA, has less than 2 parts of impurities per 10 15 parts of volume.

The hardest

Carbon (C). In its allotropic form, diamond has a Knoop hardness of 8400. Known since prehistoric times.

Dearest

Californian (Cf) was sold in 1970 at a price of $10 per microgram. Opened in 1950 by Seaborg (USA) and his colleagues.

The most flexible

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

Highest tensile strength

Boron (B) – 5.7 GPa. Discovered in 1808 by Gay-Lussac and Thénard (France) and H. Davy (Great Britain).

Melting/boiling point

Lowest. Among non-metals, helium-4 (4He) has the lowest melting point -272.375°C at a pressure of 24.985 atm and the lowest boiling point -268.928°C. Helium was discovered in 1868 by Lockyer (Great Britain) and Jansen (France). Monatomic hydrogen (H) must be an incompressible superfluid gas. Among metals, the corresponding parameters for mercury (Hg): –38.836°C (melting point) and 356.661°C (boiling point).

The tallest. Among non-metals, the highest melting point and boiling point is carbon (C), known since prehistoric times: 530°C and 3870°C. However, it seems controversial that graphite is stable at high temperatures. Transitioning from a solid to a vapor state at 3720°C, 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). Opened in 1783 by H.H. and F. d'Eluyarami (Spain).

Isotopes

The largest number of isotopes (36 each) is found in xenon (Xe), discovered in 1898 by Ramsay and Travers (Great Britain), and in cesium (Cs), discovered in 1860 by Bunsen and Kirchhoff (Germany). Hydrogen (H) has the smallest amount (3: protium, deuterium and tritium), discovered in 1776 by Cavendish (Great Britain).

The most stable. Tellurium-128 (128 Te), according to double beta decay, has a half-life of 1.5 10 24 years. Tellurium (Te) was discovered in 1782 by Müller von Reichenstein (Austria). The isotope 128 Te was first discovered in its natural state in 1924 by F. Aston (Great Britain). Data on its superstability were again confirmed in 1968 by studies by E. Alexander Jr., B. Srinivasan and O. Manuel (USA). The alpha decay record belongs to samarium-148 (148 Sm) – 8·10 15 years. The beta decay record belongs to the cadmium isotope 113 (113 Cd) – 9·10 15 years. Both isotopes were discovered in their natural state by F. Aston, respectively, in 1933 and 1924. The radioactivity of 148 Sm was discovered by T. Wilkins and A. Dempster (USA) in 1938, and the radioactivity of 113 Cd was discovered in 1961 by D. Watt and R. Glover (Great Britain).

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

Liquid series

Given the difference between melting point and boiling point, the element with the shortest liquid range is the noble gas neon (Ne) - just 2.542 degrees (-248.594°C to -246.052°C), while the longest liquid range (3453 degrees) characteristic of the radioactive transuranic element neptunium (Np) (from 637°C to 4090°C). However, if we take into account the true series of liquids - from the melting point to the critical point - then the element helium (He) has the shortest period - only 5.195 degrees (from absolute zero to -268.928 ° C), and the longest - 10200 degrees - for tungsten (from 3420°C to 13,620°C).

The most poisonous

Among non-radioactive substances, the most stringent restrictions are set for beryllium (Be) - the maximum permissible concentration (MAC) of this element in the air is only 2 μg/m3. Among the radioactive isotopes existing in nature or produced by nuclear installations, the most stringent limits on the content in the air are set for thorium-228 (228 Th), which was first discovered by Otto Hahn (Germany) in 1905 (2.4 10 –16 g/m 3), and in terms of content in water – for radium-228 (228 Ra), discovered by O. Gan in 1907 (1.1·10 –13 g/l). From an environmental point of view, they have significant half-lives (i.e. over 6 months).

Guinness Book of Records, 1998

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 mass.
Universe. Discovered in 1772 by Rutherford (Great Britain).

Hydrogen (H), 90% of the total substance.

Discovered in 1776 by Henry Cavendish (Great Britain).
Rarest (out of 94)
Lithosphere.
Astatine (At): 0.16 g in the earth's crust. Opened in 1940 by Corson (USA) and employees. The naturally occurring isotope astatine 215 (215At) (discovered in 1943 by B. Karlik and T. Bernert, Austria) exists in quantities of only 4.5 nanograms.

Atmosphere.

Radon (Rn): 2.4 kg total (6·10–20 volume of one part per million). Opened in 1900 by Dorn (Germany).
The concentration of this radioactive gas in areas of granite rock deposits is believed to have caused a number of cancers. The total mass of radon found in the earth’s crust, from which atmospheric gas reserves are replenished, is 160 tons.
Metal.
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).

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. Discovered in 1804 by Tennant (Great Britain).

Element 108, or unniloctium (Uno).

This provisional name is given by the International Union of Pure and Applied Chemistry (IUPAC).

Obtained in April 1984 by G. Münzenberg and coworkers (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, a message appeared that this element was also obtained by Yu.Ts. Oganesyan and collaborators at the Joint Institute for Nuclear Research, Dubna, USSR.

A single unnilenium atom (Une) was obtained by bombarding bismuth with iron ions in the laboratory of the Heavy Ion Research Society, Darmstadt, West Germany, on August 29, 1982. It has the highest atomic number (element 109) and the highest 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 (preliminary name - 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 its allotropic form, diamond has a Knoop hardness of 8400. Known since prehistoric times.

Dearest

Californian (Cf) was sold in 1970 at a price of $10 per microgram. Opened in 1950 by Seaborg (USA) and employees.

The most flexible

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

Highest tensile strength

Lowest.
Boron (B) – 5.7 GPa. Discovered in 1808 by Gay-Lussac and Thénard (France) and H. Davy (Great Britain).
The tallest.
Among non-metals, the highest melting point and boiling point is carbon (C), known since prehistoric times: 530°C and 3870°C. However, it seems controversial that graphite is stable at high temperatures. Transitioning from a solid to a vapor state at 3720°C, 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). Opened in 1783 by H.H. and F. d'Eluyarami (Spain).

Isotopes

Largest number of 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). Hydrogen (H) has the smallest amount (3: protium, deuterium and tritium), discovered in 1776 by Cavendish (Great Britain).

The most stable

Tellurium-128 (128Te), according to double beta decay, has a half-life of 1.5 1024 years. Tellurium (Te) was discovered in 1782 by Müller von Reichenstein (Austria). The 128Te isotope was first discovered in its natural state in 1924 by F. Aston (Great Britain). Data on its superstability were again confirmed in 1968 by studies by E. Alexander Jr., B. Srinivasan and O. Manuel (USA). The alpha decay record belongs to samarium-148 (148Sm) – 8·1015 years. The beta decay record belongs to the cadmium isotope 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 was discovered in 1961 by D. Watt and R. Glover (Great Britain).

The 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 set for beryllium (Be) - the maximum permissible concentration (MAC) of this element in the air is only 2 μg/m3. Among the radioactive isotopes existing in nature or produced by nuclear installations, the most stringent limits on the content in the air are set 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. Gan in 1907 (1.1·10–13 g/l). From an environmental point of view, they have significant half-lives (i.e. over 6 months).

Man has always sought to find materials that leave no chance for his competitors. Since ancient times, scientists have been looking for the hardest materials in the world, the lightest and the heaviest. The thirst for discovery led to the discovery of an ideal gas and an ideal black body. We present to you the most amazing substances in the world.

1. The blackest substance

The blackest substance in the world is called Vantablack and consists of a collection of carbon nanotubes (see carbon and its allotropes). Simply put, the material consists of countless “hairs”, once caught in them, the light bounces from one tube to another. In this way, about 99.965% of the light flux is absorbed and only a tiny fraction is reflected back out.
The discovery of Vantablack opens up broad prospects for the use of this material in astronomy, electronics and optics.

2. The most flammable substance

Chlorine trifluoride is the most flammable substance ever known to mankind. It is a strong oxidizing agent and reacts with almost all chemical elements. Chlorine trifluoride can burn concrete and easily ignite glass! The use of chlorine trifluoride is practically impossible due to its phenomenal flammability and the impossibility of ensuring safe use.

3. The most poisonous substance

The most powerful poison is botulinum toxin. We know it under the name Botox, which is what it is called in cosmetology, where it has found its main application. Botulinum toxin is a chemical produced by the bacteria Clostridium botulinum. In addition to the fact that botulinum toxin is the most toxic substance, it also has the largest molecular weight among proteins. The phenomenal toxicity of the substance is evidenced by the fact that only 0.00002 mg min/l of botulinum toxin is enough to make the affected area deadly to humans for half a day.

4. The hottest substance

This is the so-called quark-gluon plasma. The substance was created by colliding gold atoms at near light speed. Quark-gluon plasma has a temperature of 4 trillion degrees Celsius. For comparison, this figure is 250,000 times higher than the temperature of the Sun! Unfortunately, the lifetime of matter is limited to a trillionth of one trillionth of a second.

5. The most caustic acid

In this nomination, the champion is fluoride-antimony acid H. Fluoride-antimony acid is 2×10 16 (two hundred quintillion) times more caustic than sulfuric acid. It is a very active substance and can explode if a small amount of water is added. The fumes of this acid are deadly poisonous.

6. The most explosive substance

The most explosive substance is heptanitrocubane. It is very expensive and is used only for scientific research. But the slightly less explosive octogen is successfully used in military affairs and in geology when drilling wells.

7. The most radioactive substance

Polonium-210 is an isotope of polonium that does not exist in nature, but is manufactured by humans. Used to create miniature, but at the same time, very powerful energy sources. It has a very short half-life and is therefore capable of causing severe radiation sickness.

8. The heaviest substance

This is, of course, fullerite. Its hardness is almost 2 times higher than that of natural diamonds. You can read more about fullerite in our article The Hardest Materials in the World.

9. The strongest magnet

The strongest magnet in the world is made of iron and nitrogen. At present, details about this substance are not available to the general public, but it is already known that the new super-magnet is 18% more powerful than the strongest magnets currently in use - neodymium. Neodymium magnets are made from neodymium, iron and boron.

10. The most fluid substance

Superfluid Helium II has almost no viscosity at temperatures close to absolute zero. This property is due to its unique property of leaking and pouring out of a vessel made of any solid material. Helium II has prospects for use as an ideal thermal conductor in which heat does not dissipate.