radioactive metals. Radioactive metal and its properties

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). For different elements radioactive decay can last from a few milliseconds to several thousand years.

Next to the name of a radioactive element is often indicated by its mass number. isotope. For example, Technetium-91 or 91Tc. Different isotopes of the same element, as a rule, 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, actinium, thorium, protactinium and uranium. Their most stable isotopes occur naturally, often as ore. All other metals on the list are man-made.

most radioactive metal

The most radioactive metal at the moment - livermorium. Its isotope Livermorium-293 disintegrates in just 61 milliseconds. This isotope was first obtained in Dubna in 2000.

Another highly radioactive metal is ununpentium. 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 or more days, even one gram of this substance heats up to 500 ° C, and the radiation can instantly kill a person.

What is radiation

Everyone knows that radiation very dangerous and it is better to stay away from radioactive radiation. It is difficult to argue with this, although in reality we are constantly exposed to radiation, wherever we are. There are quite a few in the ground 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 a 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, it turns into a stable lead.

Science identifies 3 main types of radioactive radiation

alpha radiation(α) is the flow of alpha particles, positively charged. They are relatively large in size and do not pass well even through clothing or paper.

beta radiation(β) is the flux of negatively charged beta particles. They are quite small, easily pass through clothes and penetrate into skin cells, which causes great harm 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 contain a lot of energy. A cluster of gamma particles emits a bright glow. Gamma particles even pass through dense materials, making them very dangerous to living beings. They are stopped only by the densest materials, such as lead.

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.

The study of radioactive elements

The discoverer of radioactivity is Wilhelm Roentgen. In 1895, this Prussian physicist first observed radioactive radiation. Based on this discovery, a 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 in its pure form received the first radioactive metal - radium. Curie, although he discovered the first radioactive element, however, did not have time to properly study it. And the outstanding properties of radium led to the quick 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 radioactive radiation.

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

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

Extraction and synthesis

Even natural 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;
• isolation of pure uranium from the resulting solution;
• conversion of uranium to a solid state.

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

The 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 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.

Among all the elements of the periodic system, a significant part belongs to those that most people talk about 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 quite a lot of them, they are located in the periodic system immediately after lead and up to the very last cell. The main criterion by which it is customary to attribute one or another element to the radioactive group is its ability to have a certain half-life.

In other words, it is the transformation of the metal nucleus into another, child, which is accompanied by the emission of radiation of a certain type. At the same time, transformations of one element into another take place.

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

Types of radiation

The main variants of 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 occurs in nature and in the simplest way, under the influence of external forces, over time it is transformed into other forms (shows its radioactivity and decays).

The second group is metals artificially created by scientists, capable of rapid decay and powerful release of large amounts of radiation. This is done for use in certain areas of activity. Installations in which nuclear reactions are produced by the transformation of one element into another are called synchrophasotrons.

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

Fundamentals of designation of similar atoms

Since most elements have only one or two isotopes that are radioactive, it is customary to indicate a specific type in the 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 under consideration can vary greatly. There are isotopes that exist for only 0.032 seconds. But on a par with them there are those that decay for millions of years in the bowels of the earth.

Radioactive metals: list

A complete list of all the 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 those standing in the periodic system after lead, including the group That is, bismuth, polonium, astatine, radon, francium, radium, rutherfordium, and so on in serial numbers.

Above the indicated border there are many representatives, each of which also has isotopes. However, 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 that exhibit the properties of radioactivity - the vast majority. Some of them are safe due to a too long half-life and are found in nature, while others are artificially created by man for various needs in science and technology and are extremely dangerous for the human body.

Characterization of radium

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

The etymology of the word takes its roots from the French language, in which it sounds like radium. A total of 14 isotopic modifications of this element are known. But the most stable forms with mass numbers are:

Form 226 has a pronounced radioactivity. By itself, radium is a chemical element at number 88. Atomic mass. How simple matter is capable of existence. It is a silvery-white radioactive metal with a melting point of about 670 0 C.

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 to form an oxide.

Properties and application

Radium is also a chemical element that forms a series of salts. Its nitrides, chlorides, sulfates, nitrates, carbonates, phosphates, chromates are known. Also available with tungsten and beryllium.

The fact that radium-226 can be hazardous to health was not immediately recognized by its discoverer Pierre Curie. However, he managed to verify this when he conducted an experiment: for a day he walked with a test tube with metal tied to the shoulder of his arm. 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 spouses did not refuse 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. Ocean water level shift indicator.
2. Used to determine the amount of uranium in the rock.
3. Included in lighting mixtures.
4. In medicine, it is used to form therapeutic radon baths.
5. Used to remove electrical charges.
6. With its help, flaw detection of casting is carried out and 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 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, the most common and practically important variety is plutonium-239. Known chemical reactions of this metal 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, lung diseases.

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 that is comparable to 4 tons of burned coal. That is why this one finds such wide application 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 reach five years.

Uranus is a source of radiation

This element was discovered in 1789 by the German chemist Klaproth. However, people managed to explore its properties and learn how to put them into practice only in the 20th 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 mica.
2. Uraninite.
3. Nasturan.
4. Otenitis.
5. Tuyanmunit.

Three stable natural isotopes and 11 artificially synthesized isotopes are known, 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 previous considered metals - accumulation leads to an increased dose of radiation and the occurrence of cancerous tumors.

Transuranium elements

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

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

However, its radioactivity is many times greater than the indicators of the second element in terms of 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 chemists.

Thorium

It was discovered back 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.

The main use in is not based on the ability to emit a huge amount of thermal energy when decaying. 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

Silver-white radioactive metal number 84 in the periodic system. It was discovered by the same ardent researchers of radioactivity and everything connected with it, the spouses Marie and Pierre Curie in 1898. The main feature of this substance is that it freely exists 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 to make nuclear weapons. The quantity is strictly limited and is under the control of each state.

It is also used for air ionization, elimination of static electricity in the room, in the manufacture of space heaters and other similar items.

Impact 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 with sweat at all.

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

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

1. for the sake of Russian-English scientific and technical dictionary
2. for the sake of

   for the sake of
   kwa ajili wa, makusudi;
   for God's sake - lilahi;
   for what? - kwa vipi?

   Russian-Swahili dictionary
3. for the sake of

   preposition + gender P.
   
   
   
   2) unfold

   Russian-Spanish dictionary
4. for the sake of

   (what/whom)
   1) (for) fur (A)
   for the common good - für das Gemeinwohl
   2) (due to) wegen (G), um (G) ... willen
   for me - meinetwegen, um meinetwillen
   why should I..? - weswegen muß ich..?
   for the sake of friendship - aus Freundschaft
   3) unfold (from some

   Russian-German dictionary
5. for the sake of

   suggestion
   1) (in the interests) per, in favor, 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) (for the purpose) 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? - minka tahden?

   Russian-Finnish dictionary
8. for the sake of

   preposition + gender P.
   1) (in the interests of someone, something) para, por, en provecho de
   for him, them, etc. - para (por) el, ellos, etc.
   for the common good - para (por) el bien publico
   2) unfold

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

    Icun
    for you I am ready to do it - sizler içün bunı yapmağa azırım

    Russian-Crimean Tatar Dictionary
11. for the sake of

    and (c) فى
    aa (on) على

    Russian-Arabic Dictionary
12. for the sake of

    because of, for the sake of
    zarardi, for

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

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

    Russian-Portuguese Dictionary
15. for the sake of

    (whom/what) receiver
    for the sake of
    =============
    type of word: glad
    (who/what)
    names. female kind
    1. proposition
    2. sleepy discussion of some kind of food
    3. collegiate body as an organization, established
    4. organ of sovereign power
    advice n. husband.

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

    someone/something
    kedveert vki,vmi ~

    Russian-Hungarian dictionary
18. for the sake of

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

    Russian-Estonian dictionary

Radium

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

◁ Radium, th, th. R ore.

(lat. Radium), Ra, a chemical element of group II of the periodic system, belongs to the alkaline earth metals. Radioactive; the most stable isotope is 226 Ra (half-life 1600 years). Name from lat. radius - ray. Silvery white shiny metal; density 5.5-6.0 g / cm 3, t pl 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 226Ra isotope mixed with beryllium is used to prepare the simplest laboratory sources of neutrons.

RADIUM (lat. Radium), Ra (read "radium"), a radioactive chemical element, atomic number 88. It has no stable nuclides. It is located in group IIA, 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 (valency II). The radius of the neutral atom is 0.235 nm, the radius of the Ra 2+ ion is 0.162 nm (coordination number 6). The successive ionization energies of a neutral atom correspond to 5.279, 10.147, and 34.3 eV. Electronegativity according to Pauling (cm. PAULING Linus) 0,97.
Discovery history
Radium (like polonium (cm. POLONIUM) ) was discovered 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 the nuclei of atoms Ra (from the Latin radius - a ray). The titanic work of the Curie spouses to extract radium, to obtain the first milligrams of pure chloride of this element RaCl 2 became a symbol of the selfless work of research scientists. For their work on the study of radioactivity, the Curie spouses received the Nobel Prize in physics in 1903, and M. Curie in 1911 received the Nobel Prize in chemistry. In Russia, the first preparation of radium was obtained in 1921 by V. G. Khlopin (cm. Khlopin Vitaly Grigorievich) and I. Ya. Bashilov. (cm. BASHILOV Ivan Yakovlevich)
Being in nature
The content in the earth's crust is 1 10 -10% by weight. Radionuclides Ra 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 trace amounts in natural waters.
Receipt
Radium is isolated from uranium ore processing wastes by precipitation, fractional crystallization and ion exchange (cm. ION EXCHANGE) . Radium metal is obtained by electrolysis of a RaCl 2 solution using a mercury cathode or by reduction of radium oxide RaO with aluminum metal. (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 rays 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 in 1 s (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.
Chemical properties 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, forming a strong base Ra (OH) 2:
Ra + 2H 2 O \u003d 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 become yellow or brown. Sulfide RaS, nitride Ra 3 N 2 , hydride RaH 2 , carbide RaC 2 have been synthesized.
RaCl 2 chloride, RaBr 2 bromide and RaI 2 iodide, Ra(NO 3) 2 nitrate. highly soluble salts. Sulfate RaSO 4, carbonate RaSO 3 and fluoride RaF 2 are poorly soluble. Compared to other alkaline earth metals, radium (Ra 2+ ion) has a weaker tendency to complex formation.
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 radium that enters the body accumulates in the bone tissue. Large concentrations of radium cause osteoporosis, spontaneous fractures and tumors.
Features of work
In Russia, spent radium preparations are handed over to the service for the reception of radioactive waste (NPO Radon). Permissible concentration in atmospheric air for different radium nuclides is 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:

Me, husband. Nov.Otch.: Radievich, Radievna. Derivatives: Radia; Radik; Adya.Origin: (The use of common noun radium (the name of a chemical element) as a personal name.) Dictionary of personal names. RADIUM Derived from the name of the chemical element ... ... Dictionary of personal names

- (Ra) radioactive chem. element II gr. periodic system, serial number 88, mass number 226. Discovered in 1898 by Pierre and Marie Curie (when studying 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; open in 1899 by the Curies. It has not yet been obtained in pure form. Differs in ability to radiation. Rays are similar to x-rays. Dictionary of foreign words included in ... ... Dictionary of foreign words of the Russian language

- (symbol Ra), 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, present in uranium ores, was isolated by Marie CURIE in 1911. Radium ... ... Scientific and technical encyclopedic dictionary

RADIUM- radioactive chem. element, symbol Ra (lat. Radium), at. n. 88, at. m of the longest-lived isotope 226.02 (half-life 1600 years). As a decay product of uranium, radium can accumulate in fairly large quantities. On the example of R. it was ... ... Great Polytechnic Encyclopedia

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

RADIUM, radium, pl. no, husband. (from lat. radius beam) (chemical, physical). A chemical element, a metal that has the ability to radiate thermal and radiant energy, while disintegrating into a series of simple substances. Radium treatment. Dictionary… … Explanatory Dictionary of Ushakov

RADIUM, me, husband. The chemical element is a metal that has radioactive properties. | adj. radium, oh, oh. Explanatory dictionary of Ozhegov. S.I. Ozhegov, N.Yu. Shvedova. 1949 1992 ... Explanatory dictionary of Ozhegov