Neon ( Ne , lat. Neon ) is a chemical element of the 18th group, the second period of the periodic system with atomic number 10. The fifth most abundant element of the Universe after hydrogen , helium , oxygen and carbon . As a simple substance, it is an inert monatomic gas without color and odor. It was discovered (along with xenon and argon ) in 1898 by removing hydrogen , oxygen , argon and carbon dioxide from liquid air.
| Neon | ||||
|---|---|---|---|---|
| β Fluoride | Sodium β | ||||
| ||||
| The appearance of a simple substance | ||||
| Inert gas without color , taste or smell | ||||
 Neon in a vessel | ||||
| Atom properties | ||||
| Name, symbol, number | Neon / Neon (Ne), 10 | |||
| Atomic mass ( molar mass ) | 20.1797 (6) [1] a. E. m. ( g / mol ) | |||
| Electronic configuration | [He] 2s 2 2p 6 | |||
| Atom radius | ? (38) [2] pm | |||
| Chemical properties | ||||
| Covalent radius | 58 [2] pm | |||
| Ion radius | 112 [2] pm | |||
| Electronegativity | 4.4 (Pauling scale) | |||
| Electrode potential | 0 | |||
| Oxidation state | 0 | |||
| Ionization energy (first electron) | 2079.4 (21.55) kJ / mol ( eV ) | |||
| Thermodynamic properties of a simple substance | ||||
| Density (at N. at. ) | tv 1.444 g / cmΒ³ (at 24.66 K); | |||
| Melting temperature | 24.55 K; β248.6 Β° C | |||
| Boiling temperature | 27.1 K; β246.05 Β° C | |||
| Critical point | 44.4 K , 2.65 MPa | |||
| Beats heat of vaporization | 1.74 kJ / mol | |||
| Molar heat capacity | 20.79 [3] J / (K Β· mol) | |||
| Molar volume | 16.8 cmΒ³ / mol | |||
| The crystal lattice of a simple substance | ||||
| Lattice structure | cubic face-centered | |||
| Lattice options | 4.430 Γ | |||
| Debye temperature | 63,00 K | |||
| Other characteristics | ||||
| Thermal conductivity | (300 K) (0,0493) W / (mK) | |||
| CAS Number | 7440-01-9 | |||
| ten | Neon |
Ne 20,1797 | |
| 2s 2 2p 6 | |
History
Neon was discovered in June 1898 by English chemists William Ramsay and Maurice Travers [4] . They isolated this inert gas by the βexclusion methodβ after oxygen, nitrogen, and increasingly heavier air components were liquefied. In December 1910, the French inventor Georges Claude created a gas discharge lamp filled with neon.
Name Origin
The name comes from Greek. Ξ½ΞΞΏΟ - new.
There is a legend according to which the name was given to the element by the thirteen-year-old son of Ramsay - Willy, who asked his father what he was going to name the new gas, noting at the same time that he would like to give him the name novum (lat. - new). His father liked this idea, but he considered that the name neon , formed from the Greek synonym, would sound better [5] .
Prevalence
In the Universe
In world matter, neon is distributed unevenly, but in general, according to its prevalence in the Universe, it takes the fifth place among all elements - about 0.13% [6] by mass. The highest concentration of neon is observed on the Sun and other hot stars , in gas nebulae , in the atmosphere of the outer planets of the solar system - Jupiter , Saturn , Uranus , Neptune [3] . In the atmosphere of many stars, neon takes third place after hydrogen and helium [7] .
Earth's crust
Of all the stable elements of the second period, neon is the most rare on Earth [8] . Within the eighth group, neon is third in content in the earth's crust - after argon and helium [8] . Gas nebulae and some stars contain neon many times more than on Earth.
On Earth, the highest concentration of neon is observed in the atmosphere - 1.82β 10 β3 % [3] [9] by volume, and its total reserves are estimated at 7.8β 10 14 mΒ³ [3] . 1 mΒ³ of air contains about 18.2 cmΒ³ of neon (for comparison: only 5.2 cmΒ³ of helium is contained in the same volume of air) [9] . The average neon content in the earth's crust is small - 7β 10 β9 % by mass [3] . In total, about 6.6 610 10 tons of neon on our planet . In igneous rocks there are about 10 9 tons of this element [10] . As the destruction of the rocks, the gas escapes into the atmosphere. To a lesser extent, the atmosphere is supplied with neon and natural waters.
Scientists see the reason for the neon poverty of our planet in the fact that once the Earth lost its primary atmosphere, which took away the bulk of inert gases, which could not, like oxygen and other gases, chemically bind to other elements in minerals and thereby gain a foothold the planet .
Definition
Qualitatively, neon is determined by the emission spectra (characteristic lines 585.25 nm and 540.05 nm), quantitatively by mass spectrometric and chromatographic methods of analysis [3] .
Physical Properties
- Noble gases are colorless monatomic gases with no taste or smell.
- Inert gases have a higher electrical conductivity compared to other gases and when current passes through them, they shine brightly, in particular, neon with a fiery red light, since its brightest lines lie in the red part of the spectrum.
- The saturation of the outer electron shells of inert gas atoms leads to lower points of liquefaction and solidification than other gases with similar molecular weights.
Chemical Properties
All noble gases have a complete electron shell , so they are chemically inert. The chemical inertness of neon is exceptional, in this only helium can compete with it. So far, not one of its valence compounds has been obtained. Even the so-called clathrate compounds of neon with water (Ne Β· 6H 2 O), hydroquinone, and other substances (such compounds of heavy noble gases β radon, xenon, krypton, and even argon β are widely known) are very difficult to obtain and store.
However, using the methods of optical spectroscopy and mass spectrometry, the existence of ions Ne + , (NeAr) + , (NeH) + , and (HeNe) + was established .
Isotopes
There are three stable neon isotopes : 20 Ne ( isotopic abundance 90.48%), 21 Ne (0.27%) and 22 Ne (9.25%) [11] .
In addition to the three stable neon nuclides, there are sixteen other unstable isotopes. Lung 20 Ne prevails everywhere.
In many alpha-active minerals, the relative content of heavy 21 Ne and 22 Ne is tens and hundreds of times higher than their content in air. This is due to the fact that the main mechanisms of the formation of these isotopes are nuclear reactions that occur during the bombardment of aluminum , sodium , magnesium and silicon nuclei by the decay products of heavy element nuclei. In addition, similar reactions occur in the earth's crust and atmosphere under the influence of cosmic radiation.
A number of unproductive nuclear reactions have also been recorded [12] , in which 21 Ne and 22 Ne are formed - this is the capture of alpha particles by the nuclei of heavy oxygen 18 O and fluorine 19 F:
The source of the 20 Ne light nuclide prevailing on Earth has not yet been established.
Usually, Neon-20 is formed in stars due to an alpha process in which an alpha particle is absorbed by the nucleus of an oxygen atom.
with gamma ray emission:
- ;
But this process requires a temperature of more than 100 million degrees and the mass of the star more than three solar.
It is quite possible that the source of the isotope was a supernova, after the explosion of which a gas-dust cloud was formed, from which a solar system was formed.
It is believed that in outer space neon is also predominantly represented by the light nuclide 20 Ne. Many 21 Ne and 22 Ne are found in meteorites, but these nuclides are supposedly formed in the meteorites themselves under the influence of cosmic rays during wanderings in the Universe.
Getting
Neon is produced together with helium as a by-product in the process of liquefaction and separation of air in large industrial plants. Separation of the βneon-heliumβ mixture is carried out in several ways due to adsorption and condensation and low-temperature distillation.
The adsorption method is based on the ability of neon, unlike helium, to be adsorbed by activated carbon cooled by liquid nitrogen . The condensation method is based on the freezing of neon while cooling the mixture with liquid hydrogen, the distillation method is based on the difference in the boiling points of helium and nitrogen.
Neon is extracted from air in apparatus for double rectification of liquid air . Gaseous neon and helium accumulate in the upper part of the high-pressure column, that is, in the condenser-evaporator, from where they are fed under pressure of about 0.55 MPa into the tube space of the reflux condenser cooled by liquid N 2 . An enriched mixture of Ne and He is sent from the reflux condenser to purify N 2 from activated charcoal adsorbers, from which it enters the gas tank after heating (Ne + He content up to 70%); the degree of extraction of the gas mixture is 0.5-0.6. The final purification of N 2 and the separation of Ne and He can be carried out either by selective adsorption at the temperature of liquid N 2 , or by condensation methods using liquid H 2 or Ne. When using liquid hydrogen, an additional hydrogen impurity is removed using CuO at 700 Β° C. The result is neon of 99.9% purity by volume [3] .
The main industrial method for producing neon (in the last decade) is the separation of a neon-helium mixture by means of low-temperature rectification - a mixture of neon and helium is preliminarily purified from nitrogen and hydrogen impurities (hydrogen is burned in a furnace filled with a catalyst), and nitrogen in low-temperature reflux condensers and in a cryogenic unit adsorbers filled with activated carbon (coal is cooled by coils with nitrogen boiling in them under vacuum). After nitrogen removal, the neon-helium mixture is compressed by the compressor and enters the distillation column (pre-cooled to the temperature of nitrogen boiling under vacuum) for separation. To lower the temperature, the cooled mixture is throttled from 25 MPa to 0.2-0.3 MPa (depending on the operating mode of the installation). In the upper part of the column, from under the cap of the condenser, helium with an admixture of up to 20% neon is taken, in the lower part of the column neon is obtained in liquid form. As a refrigeration cycle, a throttle refrigeration cycle with a clean neon coolant is used. The distillation method of separation of the neon-helium mixture allows to obtain neon with a purity of up to 99.9999%.
Industrial plants for the production of high-purity neon have been built and are successfully operating in Ukraine - Mariupol (Ingaz enterprise) and Odessa (Aisblik enterprise), Moscow in the Russian Federation .
Application
Liquid neon is used as a cooler in cryogenic plants . Previously, neon was used in industry as an inert medium, but was replaced by cheaper argon . Neon is filled with discharge lamps , signal lamps in electronic equipment, photocells, rectifiers. A mixture of neon and helium is used as a working medium in gas lasers ( helium-neon laser ).
Tubes filled with a mixture of neon and nitrogen, when an electric discharge is passed through them, give a red-orange glow, and therefore they are widely used in advertising. By tradition, βneonβ is also often called discharge tubes of other colors, in reality using the glow of other noble gases or a fluorescent coating (see right). To obtain any color other than red, an electric discharge in argon is used with the addition of small amounts of mercury vapor in gas tubes, internally coated with a phosphor of the desired glow color, converting the ultraviolet radiation of the discharge into visible light, or a discharge in a mixture of other noble gases .
Neon lamps are used for signaling purposes at lighthouses and airfields, since their red color is very weakly scattered by fog and mist.
Physiological Action
Inert gases have a physiological effect, which is manifested in their narcotic effects on the body. The narcotic effects of neon (like helium) under normal pressure are not recorded in experiments, and when the pressure rises, the symptoms of the βneurological high pressure syndromeβ (NSDS) are the first to appear [13] .
In this regard, along with helium, neon in the composition of the neon-helium mixture is used for breathing oceanauts, divers, people working at high pressures to avoid gas embolism and nitrogen anesthesia . The advantage of the mixture is that it cools the body less, since the thermal conductivity of neon is less than helium.
Light neon-helium air also facilitates the condition of patients suffering from respiratory disorders.
A high concentration of neon in the inhaled air can cause dizziness, nausea, vomiting, loss of consciousness, and death from asphyxiation [14] [15] .
Notes
- β Michael E. Wieser, Norman Holden, Tyler B. Coplen, John K. BΓΆhlke, Michael Berglund, Willi A. Brand, Paul De BiΓ¨vre, Manfred GrΓΆning, Robert D. Loss, Juris Meija, Takafumi Hirata, Thomas Prohaska, Ronny Schoenberg , Glenda O'Connor, Thomas Walczyk, Shige Yoneda, Xiang β Kun Zhu. Atomic weights of the elements 2011 (IUPAC Technical Report ) // Pure and Applied Chemistry . - 2013 .-- Vol. 85 , no. 5 . - P. 1047-1078 . - DOI : 10.1351 / PAC-REP-13-03-02 .
- β 1 2 3 Size of neon in several environments . www.webelements.com. Date of treatment July 8, 2009.
- β 1 2 3 4 5 6 7 8 Chemical Encyclopedia: in 5 tons / Editorial Board: I. L. Knunyants (Ch. Ed.). - Moscow: Big Russian Encyclopedia, 1992. - T. 3. - S. 209-210. - 639 p. - 50,000 copies. - ISBN 5-85270-039-8.
- β William Ramsay , Morris W. Travers . On the Companions of Argon // Proceedings of the Royal Society of London. - 1898. - Vol. 63.878 . - P. 437-440 .
- β Mary Elvira Weeks. Xviii. The inert gases // Discovery of the elements: collected reprints of a series of articles published in the Journal of Chemical Education . - 3rd ed. rev. - Kila, MT: Kessinger Publishing, 2003 .-- P. 286-288. - 380 p. - ISBN 0766138720 9780766138728.
- β Neon: geological information . www.webelements.com. Date of treatment July 8, 2009.
- β Finkelstein D.N. Chapter IV Inert gases on Earth and in space // Inert gases . - Ed. 2nd. - M .: Nauka, 1979. - S. 106 .-- 200 p. - (βScience and technological progressβ). - 19,000 copies.
- β 1 2 Abundance in Earth's crust (inaccessible link) . www.webelements.com. Date of treatment July 8, 2009. Archived May 23, 2008.
- β 1 2 Finkelstein D.N. Chapter IV Inert gases on Earth and in space // Inert gases . - Ed. 2nd. - M .: Nauka, 1979.- S. 78 .-- 200 p. - (βScience and technological progressβ). - 19,000 copies.
- β Finkelstein D.N. Chapter IV Inert gases on Earth and in space // Inert gases . - Ed. 2nd. - M .: Nauka, 1979. - S. 95. - 200 p. - (βScience and technological progressβ). - 19,000 copies.
- β Isotopes of neon . www.webelements.com. Date of treatment July 8, 2009.
- β Finkelstein D.N. Chapter IV Inert gases on Earth and in space // Inert gases . - Ed. 2nd. - M .: Nauka, 1979.- S. 83 .-- 200 p. - (βScience and technological progressβ). - 19,000 copies.
- β Pavlov B.N. The problem of human protection in extreme conditions of a hyperbaric habitat . www.argonavt.com (May 15, 2007). Date of treatment May 22, 2010. Archived August 22, 2011.
- β Neon (Ne) - Chemical properties, Health and Environmental effects . www.lenntech.com. Date of treatment July 8, 2009. Archived August 22, 2011.
- β Neon (ICSC ) . www.inchem.org. Date of treatment September 19, 2009. Archived August 22, 2011.