Neon

The neon is a chemical element with atomic number 10 and symbol Ne. It is a noble, colorless, practically inert gas, present in traces in the air, but very abundant in the universe, which provides a characteristic reddish tone in the light of the fluorescent lamps in which it is used.

Summary

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  • 1 History
  • 2 Main features
  • 3 Applications
  • 4 Abundance and obtaining
  • 5 Compounds
  • 6 Isotopes
  • 7 Related Links
  • 8 Reference
  • 9 Sources

History

Neon (from the Greek νεος new and -on, ending in noble gas names) was discovered by William Ramsay and Morris Travers in 1898.

Main features

It is the second lightest noble gas, and has a cooling power, per unit volume, 40 times that of liquid helium and three times that of liquid hydrogen. In most applications the use of liquid neon is cheaper than helium.

Applications

The red-orange tone of the light emitted by neon tubes is widely used for advertising indicators, others of different color are also called neon tubes that actually contain different gases. Other uses of neon that can be mentioned are: High voltage indicators.

  • Television tubes.
  • Together with helium it is used to obtain a type of laser.
  • Liquefied neon is marketed as a cryogenic refrigerant.

Abundance and obtaining

Neon is usually in the form of a monatomic gas. The earth’s atmosphere contains 15.4 ppm and is obtained by subcooling the air and distilling the resulting cryogenic liquid.

Compounds

Even though neon is inert for practical purposes, a compound with fluorine has been obtained in the laboratory. It is not clear whether this or some other different neon compound exists in nature, but some evidence suggests that this may be the case. Ne +, (NeAr) +, (NeH) + and (HeNe +) ions have been observed in optical and mass spectrometric investigations. Furthermore, neon is known to form an unstable hydrate.

Isotopes

There are three stable isotopes, Ne-20 (90.48%), Ne-21 (0.27%) and Ne-22 (9.25%). Ne-21 and Ne-22 are obtained mainly by neutron emission, and α-decay of Mg-24 and Mg-25 respectively, and their variations are well known, but not those of Ne-20 on which there are still discrepancies. Alpha particles come from the decay chains of uranium while neutrons are produced mostly by secondary reactions of α particles. As a result of these reactions, in rocks rich in uranium, such as granites, it has been observed that the Ne-20 / Ne-22 ratio tends to decrease while the Ne-21 / Ne-22 ratio increases. Analysis carried out on rocks exposed to cosmic rays have shown the generation of Ne-21 from nuclei of Mg, Na, Si and Al, suggesting that it is possible, analyzing the percentages of the three isotopes, date the exposure time of the surface rocks and meteorites. Similar to xenon, neon in volcanic gas samples is enriched for Ne-20 as well as cosmogenic Ne-21. Likewise, high amounts of Ne-20 have been found in diamonds, which leads us to think about the existence of solar neon reservoirs on earth.

 

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