1. for the sake of Russian-English Scientific and Technical Dictionary
2. for the sake of

   Radi
   kwa ajili ya, makusudi;
   radi boga - lilahi;
   for what? - kwa vipi?

   Russian-Swahili Dictionary
3. for the sake of

   preposition + gender. NS.
   
   
   
   2) decomp.

   Russian-Spanish Dictionary
4. for the sake of

   (what / who)
   1) (for) für (A)
   for the common good - für das Gemeinwohl
   2) (because of) wegen (G), um (G) ... willen
   for me - meinetwegen, um meinetwillen
   why should I ..? - weswegen muß ich ..?
   for friendship - aus Freundschaft
   3) decomp. (with smth.

   Russian-German Dictionary
5. for the sake of

   offer
   1) (in favor) per, in favore, per amore
   for the common cause - per la causa comune
   do for a friend - fare per l "amico
   
   for God's sake - per carità, per amor di Dio
   2) (with a view) per, allo scopo ...

   Russian-Italian Dictionary
6. for the sake of

   Pour
   for fun - histoire de plaisanter

   Russian-French Dictionary
7. for the sake of

   prep
   takia, tähden, vuoksi
   for me - minun takiani
   for this - tämän vuoksi
   for what? - minkä tähden?

   Finnish-Russian dictionary
8. for the sake of

   preposition + gender. NS.
   1) (in the interests of someone, something) para, por, en provecho de
   for his sake, them, etc. - para (por) él, ellos, etc.
   for the common good - para (por) el bien público
   2) decomp.

   Comprehensive Russian-Spanish Dictionary
9. for the sake of Russian-Swedish dictionary
10. for the sake of

    Içün
    for your sake I am ready to do it - sizler içün bunı yapmağa azırım

    Russian-Crimean Tatar Dictionary
11. for the sake of

    and (c) فى
    aa (na) على

    Russian-Arabic dictionary
12. for the sake of

    because of, for the sake of
    zarardi, for

    Russian-Bulgarian dictionary
13. For the sake Russian-Dutch Dictionary
14. for the sake of

    prdl
    (for smth) para, por causa de, (in the name of) em prol de; para o bem; (for the purpose of smth.) por; (because of smth) por, por causa de

    Russian-Portuguese Dictionary
15. for the sake of

    (who / who) user
    for the sake of
    =============
    from words: glad
    (who / who)
    name life family
    1.propositions, orders for children
    2.burning discussion of what kind of food
    3.the collegial body of which organization, establish
    4.the body of sovereign power
    advice noun husband.

    Ukrainian-Russian dictionary
16. for the sake of Russian-Lithuanian dictionary
17. for the sake of

    someone / something
    kedvéért vki, vmi ~

    Russian-Hungarian Dictionary
18. for the sake of

    1.kelle-mille jaoks
    2.kelle-mille nimel
    3.kelle-mille pärast

    Russian-Estonian Dictionary

Radioactive metals are metals that spontaneously emit a stream of elementary particles into the environment. This process is called alpha (α), beta (β), gamma (γ) radiation, or simply radioactive radiation.

All radioactive metals decay over time and turn into stable elements (sometimes going through a whole chain of transformations). Different elements radioactive decay can last from a few milliseconds to several thousand years.

Next to the name of a radioactive element, the mass number of its isotope... For example, Technetium-91 or 91 Tc... Different isotopes of the same element usually have common physical properties and differ only in the duration of radioactive decay.

List of radioactive metals

Radioactive elements are divided into natural(existing in nature) and artificial(obtained as a result of laboratory synthesis). There are not many natural radioactive metals - these are polonium, radium, anemones, thorium, protactinium and uranium. Their most stable isotopes occur naturally, most often in the form of ore. All other metals on the list are man-made.

The most radioactive metal

The most radioactive metal at the moment - livermore... Its isotope Livermorium-293 decays in just 61 milliseconds. For the first time this isotope was obtained in Dubna, in 2000.

Another very radioactive metal - ununpentius... Isotope ununpentium-289 has a slightly longer decay period (87 milliseconds).

Of the more or less stable, practically used substances, the most radioactive metal is considered polonium(isotope polonium-210). It is a silvery white radioactive metal. Although its half-life reaches 100 days or more, even one gram of this substance is heated to 500 ° C, and radiation can instantly kill a person.

What is radiation

Everyone knows that radiation very dangerous and it is best to stay away from radioactive radiation. It is difficult to argue with this, although in reality we are constantly exposed to the influence of radiation, wherever we are. There is a fairly large amount of radioactive ore, and from space to Earth constantly arrive charged particles.

In short, radiation is the spontaneous emission of elementary particles. Protons and neutrons are separated from the atoms of the radioactive substance, "flying away" into the external environment. At the same time, the nucleus of the atom gradually changes, turning into another chemical element. When all unstable particles are separated from the nucleus, the atom ceases to be radioactive. For example, thorium-232 at the end of its radioactive decay turns into a stable lead.

Science identifies 3 main types of radioactive radiation

Alpha radiation(α) - flux of alpha particles, positively charged. They are comparatively large in size and do not go well even through clothing or paper.

Beta radiation(β) is the flow of negatively charged beta particles. They are quite small, easily pass through clothing and penetrate into skin cells, which is very harmful to health. But beta particles do not pass through dense materials such as aluminum.

Gamma radiation(γ) is high frequency electromagnetic radiation. Gamma rays have no charge, but they contain a lot of energy. An accumulation of gamma particles emits a bright glow. Gamma particles pass even through dense materials, making them very dangerous to living things. Only the densest materials, such as lead, stop them.

All these types of radiation are present in one way or another anywhere on the planet. They are not dangerous in small doses, but at high concentrations they can cause very serious damage.

Study of radioactive elements

The discoverer of radioactivity is Wilhelm Roentgen... In 1895 this Prussian physicist observed radioactive radiation for the first time. Based on this discovery, the famous medical device was created, named after the scientist.

In 1896, the study of radioactivity continued Henri Becquerel, he experimented with uranium salts.

In 1898 Pierre Curie the first radioactive metal, Radium, was obtained in its pure form. Although Curie discovered the first radioactive element, however, he did not have time to really study it. And the outstanding properties of radium led to the rapid death of the scientist, who carelessly carried his "brainchild" in his breast pocket. The great discovery took revenge on its discoverer - Curie died at the age of 47 from a powerful dose of radiation.

In 1934, an artificial radioactive isotope was synthesized for the first time.

Nowadays, many scientists and organizations are engaged in the study of radioactivity.

Extraction and synthesis

Even naturally occurring radioactive metals do not occur in nature in their pure form. They are synthesized from uranium ore. The process of obtaining pure metal is extremely laborious. It consists of several stages:

• concentration (crushing and separation of sediment with uranium in water);
• leaching - that is, transferring the uranium precipitate into solution;
• separation of pure uranium from the resulting solution;
• conversion of uranium into a solid state.

As a result, only a few grams of uranium can be obtained from a ton of uranium ore.

Synthesis of artificial radioactive elements and their isotopes takes place in special laboratories, which create conditions for working with such substances.

Practical use

Most often, radioactive metals are used to generate energy.

Nuclear reactors are devices that use uranium to heat water and create a stream of steam that turns a turbine to generate electricity.

In general, the scope of application of radioactive elements is quite wide. They are used to study living organisms, diagnose and treat diseases, generate energy, and monitor industrial processes. Radioactive metals are the basis for the creation of nuclear weapons - the most destructive weapons on the planet.

Radium

RADIUM-I am; m.[lat. Radium from radius - ray] Chemical element (Ra), radioactive silvery-white metal (used in medicine and technology as a source of neutrons).

◁ Radium, th, th. R-th ore.

(lat. Radium), Ra, a chemical element of the II group of the periodic system, refers to alkaline earth metals. Radioactive; the most stable isotope is 226 Ra (half-life 1600 years). Name from lat. radius - ray. Silver-white shiny metal; density 5.5-6.0 g / cm 3, t mp 969 ° C. Chemically very active. It occurs naturally in uranium ores. Historically, the first element whose radioactive properties have found practical application in medicine and technology. The 226 Ra isotope mixed with beryllium is used to prepare the simplest laboratory neutron sources.

RADIUM (lat. Radium), Rа (read "radium"), a radioactive chemical element, atomic number 88. It has no stable nuclides. It is located in the IIA group, in the 7th period of the periodic system. Refers to alkaline earth elements. Electronic configuration of the outer layer of atom 7 s 2. In compounds, it exhibits an oxidation state of +2 (valence II). The radius of the neutral atom is 0.235 nm, the radius of the Rа 2+ ion is 0.162 nm (coordination number 6). The sequential ionization energies of a neutral atom correspond to 5.279, 10.147, and 34.3 eV. Pauling electronegativity (cm. POLING Linus) 0,97.
Discovery history
Radium (like polonium (cm. POLONIUM)) was opened at the end of the 19th century in France by A. Becquerel (cm. BECQUEREL Antoine Henri) and spouses P. and M. Curie (cm. Curie Pierre)... The name "radium" is associated with the radiation of atomic nuclei Ra (from the Latin radius - ray). The titanic work of the Curies to extract radium, to obtain the first milligrams of pure chloride of this element, RaCl 2, has become a symbol of the selfless work of research scientists. For their work on the study of radioactivity, the Curies in 1903 received the Nobel Prize in Physics, and M. Curie in 1911 - the Nobel Prize in Chemistry. In Russia, the first radium preparation was obtained in 1921 by V.G. Khlopin (cm. Khlopin Vitaly Grigorievich) and I. Ya. Bashilov. (cm. BASHILOV Ivan Yakovlevich)
Being in nature
Content in the earth's crust 1 · 10 -10% by weight. Ra radionuclides are part of the natural radioactive series of uranium-238, uranium-235, and thorium-232. The most stable radionuclide of radium is a-radioactive 226 Ra, with a half-life T 1/2 = 1620 years. In 1 ton of uranium (cm. Uranium (chemical element)) uranium ores contain about 0.34 g of radium. It is present in negligible concentrations in natural waters.
Receiving
Radium is isolated from uranium ore processing waste by precipitation, fractional crystallization and ion exchange (cm. ION EXCHANGE)... Metallic radium is obtained by electrolysis of a RaCl 2 solution using a mercury cathode or reduction of radium oxide RaO with metallic aluminum. (cm. ALUMINUM)
Physical and chemical properties
Radium is a silvery white metal that glows in the dark. The crystal lattice of metallic radium is body-centered cubic, parameter a= 0.5148 nm. Melting point 969 ° C, boiling point 1507 ° C, density 5.5-6.0 kg / dm 3. Ra-226 nuclei emit alpha particles with an energy of 4.777 MeV and gamma quanta with an energy of 0.188 MeV. Due to the radioactive decay of Ra-226 nuclei and daughter decay products, 1 g of Ra releases 550 J / h of heat. The radioactivity of 1 g of Ra is about 3.7 · 10 10 decays per second (3.7 · 10 10 becquerels). During radioactive decay, Ra-226 turns into radon-222. For 1 day, about 1 mm 3 Rn is formed from 1 g of Ra-2216.
Chemically similar to barium (cm. BARIUM) but more active. In air, it is covered with a film consisting of oxide, hydroxide, carbonate and radium nitride. Reacts violently with water to form a strong base Ra (OH) 2:
Ra + 2H 2 O = Ra (OH) 2 + H 2
Radium oxide RaO is a typical basic oxide. When burned in air or oxygen (cm. OXYGEN) a mixture of oxide RaO and peroxide RaO 2 is formed. Most radium salts are colorless, but when decomposed by their own radiation, they acquire a yellow or brown color. Sulfide RaS, nitride Ra 3 N 2, hydride RaH 2, carbide RaC 2 were synthesized.
Chloride RaCl 2, bromide RaBr 2 and iodide RaI 2, nitrate Ra (NO 3) 2. highly soluble salts. Sulfate RaSO 4, carbonate RaCO 3 and fluoride RaF 2 are poorly soluble. Compared to other alkaline earth metals, radium (Ra 2+ ion) has a weaker tendency to form complexes.
Application
Radium salts are used in medicine as a source of radon (cm. RADON) for the preparation of radon baths.
Content in the body
Radium is highly toxic. About 80% of the incoming radium is accumulated in the bone tissue. High concentrations of radium cause osteoporosis, spontaneous fractures and tumors.
Features of work
In Russia, spent radium preparations are handed over to the service for receiving radioactive waste (NPO Radon). The permissible concentration in atmospheric air is for different radium nuclides from 10 -4 to 10 -5 Bq / l, in water - from 2 to 13 Bq / l.

encyclopedic Dictionary. 2009 .

See what "radium" is in other dictionaries:

I am a husband. New Report: Radievich, Radievna. Derivatives: Radya; Radik; Adya Origin: (The use of the common noun radium (the name of a chemical element) as a personal name.) Dictionary of personal names. RADIUM Formed from the name of a chemical element ... ... Dictionary of personal names

- (Ra) radioactive chem. element II gr. Periodic table, serial number 88, mass number 226. Discovered in 1898 by Pierre and Marie Curie (in the study of the radioactive properties of uranium). Currently, 14 isotopes of Ra are known as natural ... Geological encyclopedia

Chemical element from the group of alkaline earth metals; opened in 1899 by the Curies. It has not yet been obtained in its pure form. Differs in the ability to radiation. The beams are similar to X-rays. Dictionary of foreign words included in ... ... Dictionary of foreign words of the Russian language

- (Ra symbol), a chemical element, a white radioactive metal from the group of ALKALINE EARTH METALS. First discovered in uranite in 1898 by Pierre and Marie Curie. This metal, which is present in uranium ores, was isolated by Maria Curie in 1911. Radium ... ... Scientific and technical encyclopedic dictionary

RADIUM- radioactive chemical. element, symbol Ra (Latin Radium), at. n. 88, at. m long-lived isotope 226.02 (half-life 1600 years). As a decay product of uranium, radium can accumulate in fairly large quantities. R.'s example was ... ... Big Polytechnic Encyclopedia

- (lat. Radium) Ra, a chemical element of group II of the periodic system, atomic number 88, atomic mass 226.0254, refers to alkaline earth metals. Radioactive; the most stable isotope 226Ra (half-life 1600 years). Name from lat ... Big Encyclopedic Dictionary

RADIUM, radium, pl. no, husband. (from Latin radius ray) (chemical, physical). A chemical element, a metal with the ability to emit thermal and radiant energy, while decaying into a successive series of simple substances. Radium treatment. Explanatory dictionary… … Ushakov's Explanatory Dictionary

RADIY, me, husband. The chemical element is a metal with radioactive properties. | adj. radium, oh, oh. Ozhegov's Explanatory Dictionary. S.I. Ozhegov, N.Yu. Shvedova. 1949 1992 ... Ozhegov's Explanatory Dictionary

Among all the elements of the periodic table, a significant part belongs to those about which most people speak with fear. How else? After all, they are radioactive, which means a direct threat to human health.

Let's try to figure out exactly which elements are dangerous, and what they are, and also find out what their harmful effect on the human body is.

General concept of a group of radioactive elements

This group includes metals. There are a lot of them, they are located in the periodic table immediately after lead and up to the very last cell. The main criterion by which it is customary to classify this or that element as radioactive is its ability to have a certain half-life.

In other words, this is the transformation of a metal nucleus into another, daughter, which is accompanied by the emission of radiation of a certain type. In this case, some elements are transformed into others.

A radioactive metal is one in which at least one isotope is present. Even if there are six varieties in total, and only one of them will carry this property, the entire element will be considered radioactive.

Types of radiation

The main options for radiation emitted by metals during decays are:

• alpha particles;
• beta particles or neutrino decay;
• isomeric transition (gamma rays).

There are two options for the existence of such elements. The first is natural, that is, when a radioactive metal is found in nature and in the simplest way, under the influence of external forces, over time is transformed into other forms (manifests its radioactivity and decays).

The second group is metals artificially created by scientists, capable of rapid decay and powerful release of a large amount of radiation. This is done for use in certain areas of activity. Installations in which nuclear reactions are carried out for the transformation of some elements into others are called synchrophasotrons.

The difference between the two indicated half-life methods is obvious: in both cases it is spontaneous, but only artificially obtained metals give precisely nuclear reactions in the process of destructuring.

Basics of notation for similar atoms

Since for most of the elements only one or two isotopes are radioactive, it is customary to indicate a specific type in designations, and not the entire element as a whole. For example, lead is just a substance. If we take into account that it is a radioactive metal, then it should be called, for example, "lead-207".

The half-lives of the particles in question can vary greatly. There are isotopes that only exist for 0.032 seconds. But on a par with them there are those that disintegrate for millions of years in the bowels of the earth.

Radioactive metals: list

A complete list of all elements belonging to the group under consideration can be quite impressive, because in total about 80 metals belong to it. First of all, these are all that stand in the periodic table after lead, including the group That is, bismuth, polonium, astatine, radon, francium, radium, rutherfordium, and so on in serial numbers.

Above the designated border, there are many representatives, each of which also has isotopes. Moreover, some of them may be just radioactive. Therefore, it is important what varieties the radioactive metal has, more precisely one of its isotopic varieties, almost every representative of the table has. For example, they have:

• calcium;
• selenium;
• hafnium;
• tungsten;
• osmium;
• bismuth;
• indium;
• potassium;
• rubidium;
• zirconium;
• europium;
• radium and others.

Thus, it is obvious that there are a lot of elements exhibiting the properties of radioactivity - the overwhelming majority. Some of them are safe due to a too long half-life and are found in nature, while the other is created artificially by humans for various needs in science and technology and is extremely dangerous for the human body.

Characteristics of radium

The name of the element was given by its discoverers - spouses and Maria. It was these people who first discovered that one of the isotopes of this metal - radium-226 - is the most stable form with special properties of radioactivity. This happened in 1898, and a similar phenomenon only became known. The spouses of chemists were engaged in its detailed study.

The etymology of the word is rooted in the French language, in which it sounds like radium. In total, 14 isotopic modifications of this element are known. But the most stable forms with mass numbers are:

Form 226 has a pronounced radioactivity. Radium itself is a chemical element at number 88. Atomic mass. As a simple substance, it is capable of existence. It is a silvery-white radioactive metal with a melting point of about 670 0 С.

From a chemical point of view, it exhibits a fairly high degree of activity and is able to react with:

• water;
• organic acids, forming stable complexes;
• oxygen, forming an oxide.

Properties and application

Also, radium is a chemical element that forms a number of salts. Known for its nitrides, chlorides, sulfates, nitrates, carbonates, phosphates, chromates. Also available with tungsten and beryllium.

The fact that radium-226 could be hazardous to health was not immediately recognized by its discoverer Pierre Curie. However, he managed to be convinced of this when he conducted an experiment: he walked for a day with a test tube with metal tied to his shoulder. A non-healing ulcer appeared at the site of contact with the skin, which the scientist could not get rid of for more than two months. The couple did not give up their experiments on the phenomenon of radioactivity, and therefore both died from a large dose of radiation.

In addition to the negative value, there are a number of areas in which radium-226 finds use and benefits:

1. Indicator of the displacement of the ocean water level.
2. Used to determine the amount of uranium in a rock.
3. Part of lighting mixtures.
4. In medicine, it is used to form therapeutic radon baths.
5. Used to remove electrical charges.
6. With its help, casting flaw detection is carried out and the seams of parts are welded.

Plutonium and its isotopes

This element was discovered in the forties of the XX century by American scientists. It was first isolated from where it was formed from neptunium. The latter is the result of the decay of the uranium nucleus. That is, they are all closely interconnected by common radioactive transformations.

There are several stable isotopes of this metal. However, plutonium-239 is the most widespread and practically important variety. Chemical reactions of this metal are known with:

• oxygen,
• acids;
• water;
• alkalis;
• halogens.

In terms of its physical properties, plutonium-239 is a brittle metal with a melting point of 640 0 C. The main methods of influencing the body are the gradual formation of oncological diseases, accumulation in bones and causing their destruction, and lung disease.

The area of ​​use is mainly the nuclear industry. It is known that during the decay of one gram of plutonium-239, such an amount of heat is released, which is comparable to 4 tons of burnt coal. That is why this one finds such widespread use in reactions. Nuclear plutonium is a source of energy in nuclear reactors and thermonuclear bombs. It is also used in the manufacture of electric energy accumulators, the service life of which can be up to five years.

Uranium is a source of radiation

This element was discovered in 1789 by a German chemist Klaproth. However, people managed to study its properties and learn how to apply them in practice only in the XX century. The main distinguishing feature is that radioactive uranium is capable of forming nuclei during natural decay:

• lead-206;
• krypton;
• plutonium-239;
• lead-207;
• xenon.

In nature, this metal is light gray in color, has a melting point of over 1100 0 C. It is found in the composition of minerals:

1. Uranium micas.
2. Uraninite.
3. Nasturan.
4. Othenit.
5. Tuyanmunit.

There are three stable natural isotopes and 11 artificially synthesized, with mass numbers from 227 to 240.

In industry, radioactive uranium is widely used, which can quickly decay with the release of energy. So, it is used:

• in geochemistry;
• mining;
• nuclear reactors;
• in the manufacture of nuclear weapons.

The effect on the human body is no different from the previously considered metals - the accumulation leads to an increased dose of radiation and the appearance of cancerous tumors.

Transuranic elements

The most important of the metals next to uranium in the periodic table are those that were recently discovered. Literally in 2004, sources were published confirming the birth of element 115 of the periodic system.

It was the most radioactive metal known to date - ununpentium (Uup). Its properties remain unexplored until now, because the half-life is 0.032 seconds! It is simply impossible to consider and identify the details of the structure and the features manifested under such conditions.

However, its radioactivity is many times higher than the indicators of the second element in this property - plutonium. Nevertheless, it is not ununpentium that is used in practice, but its "slower" comrades in the table - uranium, plutonium, neptunium, polonium and others.

Another element - unbibium - theoretically exists, but scientists from different countries have not been able to prove this in practice since 1974. The last attempt was made in 2005, but was not confirmed by the general council of chemical scientists.

Thorium

It was discovered in the 19th century by Berzelius and named after the Scandinavian god Thor. It is a weakly radioactive metal. Five of its 11 isotopes have this feature.

Its primary use is not based on the ability to emit enormous amounts of thermal energy upon decay. The peculiarity is that thorium nuclei are able to capture neutrons and turn into uranium-238 and plutonium-239, which already enter directly into nuclear reactions. Therefore, thorium can also be attributed to the group of metals we are considering.

Polonium

A silvery white radioactive metal at number 84 in the periodic table. It was discovered by the same ardent researchers of radioactivity and everything connected with it, the spouses Maria and Pierre Curie in 1898. The main feature of this substance is that it exists freely for about 138.5 days. That is, this is the half-life of this metal.

It occurs naturally in uranium and other ores. It is used as a source of energy, and quite powerful. It is a strategic metal, as it is used for the manufacture of nuclear weapons. The quantity is strictly limited and is under the control of each state.

It is also used to ionize air, eliminate static electricity in a room, in the manufacture of space heaters and other similar items.

Effects on the human body

All radioactive metals have the ability to penetrate human skin and accumulate inside the body. They are very poorly excreted with waste products, they are not excreted at all with sweat.

Over time, they begin to affect the respiratory, circulatory, and nervous systems, causing irreversible changes in them. Affect cells, causing them to function incorrectly. As a result, the formation of malignant tumors occurs, and oncological diseases occur.

Therefore, each radioactive metal is a great danger to humans, especially if we talk about them in their pure form. Do not touch them with unprotected hands and be in the room with them without special protective devices.