The neon It is a chemical element that is represented by the symbol Ne. It is a noble gas whose name in Greek means new, a quality that it was able to maintain for decades not only because of the sparkle of its discovery, but also because it adorned cities with its light as they developed their modernization..
We have all ever heard of neon lights, which actually correspond to nothing more than red-orange; unless they are mixed with other gases or additives. Today they have a bizarre air compared to recent lighting systems; however, neon is much more than just a stunning modern light source.
This gas, which consists practically of Ne atoms, indifferent to each other, represents the most inert and noble substance of all; It is the most inert element in the periodic table, and currently and formally it is not known a sufficiently stable compound. It is even more inert than helium itself, but also more expensive.
The high cost of neon is due to the fact that it is not extracted from the subsoil, as is the case with helium, but from the liquefaction and cryogenic distillation of the air; even when it is present in the atmosphere in sufficient abundance to produce a huge volume of neon.
It is easier to extract helium from natural gas reserves than to liquefy air and extract neon from it. In addition, its abundance is less than that of helium, both inside and outside the Earth. In the Universe, neon is found in novae and supernovae, as well as in regions frozen enough to prevent it from escaping..
In its liquid form, it is a much more effective refrigerant than liquid helium and hydrogen. Likewise, it is an element present in the electronics industry with regard to lasers and equipment that detect radiation..
Article index
The history of neon is closely related to that of the rest of the gases that make up the air and their discoveries. The English chemist Sir William Ramsay, together with his mentor John William Strutt (Lord Rayleigh), decided in 1894 to study the composition of air through chemical reactions.
From a sample of air they managed to deoxygenate and denitrogenize it, obtaining and discovering the noble gas argon. His scientific passion also led him to the discovery of helium, after dissolving the mineral cleveite in an acid medium and collecting characterizing the released gas..
At the time, Ramsay suspected that there was a chemical element located between helium and argon, making unsuccessful attempts to find them in mineral samples. Until finally he considered that other gases less abundant in the air should be “hidden” in argon..
Thus, the experiments that led to the discovery of neon began with condensed argon..
In his work, Ramsay, assisted by his colleague Morris W. Travers, started with a highly purified and liquefied sample of argon, which he subsequently subjected to a kind of cryogenic and fractional distillation. Thus, in 1898 and at University College London, both English chemists managed to identify and isolate three new gases: neon, krypton and xenon..
The first of these was neon, which he glimpsed when they collected it in a glass tube where they applied an electric shock; its intense red-orange light was even more striking than the colors of krypton and xenon.
It was in this way that Ramsay gave this gas the name 'neon', which in Greek means 'new'; a new element appeared from argon. Shortly after, in 1904 and thanks to this work, he and Travers received the Nobel Prize in chemistry.
Ramsay then had little to do with the revolutionary applications of neon as far as lighting is concerned. In 1902, the electrical engineer and inventor, Georges Claude, together with Paul Delorme, formed the company L'Air Liquide, dedicated to selling liquefied gases to industries and who soon saw the luminous potential of neon.
Claude, inspired by the inventions of Thomas Edison and Daniel McFarlan Moore, built the first tubes filled with neon, signing a patent in 1910. He sold his product practically under the following premise: neon lights are reserved for cities and monuments because they are very dazzling and attractive.
Since then, the rest of the history of neon to the present goes hand in hand with the appearance of new technologies; as well as the need for cryogenic systems that can use it as a cooling liquid.
Neon is a colorless, odorless, and tasteless gas. However, when an electrical discharge is applied, its atoms are ionized or excited, emitting photons of energy that enter the visible spectrum in the form of a reddish-orange flash (top image).
So the neon lights are red. The higher the gas pressure, the higher the electricity required and the reddish glow obtained. These lights illuminating the alleys or the fronts of the shops are very common, especially in cold climates; since the reddish intensity is such that it can penetrate the mist from considerable distances.
20.1797 g / mol.
10.
-248.59 ºC.
-246.046 ºC.
-Under normal conditions: 0.9002 g / L.
-From the liquid, just at the boiling point: 1.207 g / mL.
0.6964 (relative to air = 1). In other words, air is 1.4 times denser than neon. Then a balloon inflated with neon will rise into the air; although less quickly compared to one inflated with helium.
0.9869 atm at 27 K (-246.15 ° C). Note that at such a low temperature the neon already exerts a pressure comparable to atmospheric.
0.335 kJ / mol.
1.71 kJ / mol.
20.79 J / (mol K).
-First: 2080.7 kJ / mol (Ne+ gaseous).
-Second: 3952.3 kJ / mol (Netwo+ gaseous).
-Third: 6122 kJ / mol (Ne3+ gaseous).
The ionization energies for neon are particularly high. This is due to the difficulty of removing one of its valence electrons from its very small atom (compared to the other elements of its same period).
The only probable and theoretical oxidation state or number for neon is 0; that is, in its hypothetical compounds it does not gain or lose electrons, but rather interacts as a neutral atom (Ne0).
This is due to its null reactivity as a noble gas, which does not allow it to gain electrons due to the lack of an energetically available orbital; and neither to be able to lose them having positive oxidation numbers, due to the difficulty of overcoming the effective nuclear charge of its ten protons.
The aforementioned explains why a noble gas is not very reactive. However, among all the noble gases and chemical elements, neon is the owner of the true crown of nobility; it does not admit electrons in any way or from anyone, nor can it share its own because its nucleus prevents it and therefore does not form covalent bonds.
Neon is less reactive (more noble) than helium because, although its atomic radius is larger, the effective nuclear charge of its ten protons exceeds that of the two protons in the helium nucleus..
As one descends through group 18, this force decreases because the atomic radius increases considerably; and that is why the other noble gases (especially xenon and krypton) can form compounds.
To date, no remotely stable compound of neon is known. However, the existence of polyatomic cations such as: [NeAr]+, WNe3+, RhNetwo+, MoNetwo+, [NeH]+ and [NeHe]+.
Likewise, mention can be made of his Van der Walls compounds, in which although there are no covalent bonds (at least not formally), the non-covalent interactions allow them to remain cohesive under rigorous conditions..
Some such Van der Walls compounds for neon are, for example: Ne3 (trimer), ItwoNetwo, NeNiCO, NeAuF, LiNe, (Ntwo)6Ne7, NeCtwentyHtwenty (fullerene endohedral complex), etc. And also, it should be noted that organic molecules can also "rub shoulders" with this gas under very special conditions..
The detail of all these compounds is that they are not stable; moreover, most originate in the midst of a very strong electric field, where gaseous metal atoms are excited in the company of neon.
Even with a covalent (or ionic) bond, some chemists don't bother to think of them as true compounds; and therefore, neon continues to be a noble and inert element seen from all "normal" sides..
The neon atom could be visualized as an almost compact sphere due to its small size, and the large effective nuclear charge of its ten electrons, eight of which are valence electrons, according to their electronic configuration:
1stwo2stwo2 P6 or [He] 2stwo2 P6
Thus, the Ne atom interacts with its environment using its 2s and 2p orbitals. However, they are completely filled with electrons, complying with the famous valence octet.
It cannot gain more electrons because the 3s orbital is not available energetically; Besides, it cannot lose them either because of their small atomic radius and the "narrow" distance separates them from the ten protons in the nucleus. Therefore, this Ne atom or sphere is very stable, unable to form chemical bonds with practically any element..
It is these Ne atoms that define the gas phase. Being very small, its electronic cloud is homogeneous and compact, difficult to polarize and, therefore, to establish instantaneous dipole moments that induce others in neighboring atoms; that is, the scattering forces between the Ne atoms is very weak.
That is why the temperature must drop to -246 ºC so that neon can go from a gaseous state to a liquid..
Once at this temperature, the Ne atoms are close enough for dispersion forces to bind them together in a liquid; that although apparently it is not as impressive as the quantum fluid of liquid helium and its superfluidity, it has a cooling power 40 times higher than this.
This means that a liquid neon cooling system is 40 times more efficient than a liquid helium one; cools faster and maintains temperature longer.
The reason could be because, even with Ne atoms being heavier than He, the former separate and disperse more easily (heat up) than the latter; but their interactions are so weak during their collisions or encounters, that they again slow down (cool down) quickly.
When the temperature drops even further, to -248 ° C, the dispersion forces become stronger and more directional, now capable of ordering the He atoms to crystallize into a face-centered cubic (fcc) crystal. This helium fcc crystal is stable under all pressures.
Neon is the fifth most abundant chemical element in the entire Universe. Due to its lack of reactivity, high vapor pressure and light mass, it escapes from the Earth's atmosphere (although to a lesser degree than helium), and little dissolves in the seas. That is why here, in the Earth's air, it barely has a concentration of 18.2 ppm by volume..
For said concentration of neon to increase, it is necessary to lower the temperature to the neighborhood of absolute zero; conditions only possible in the Cosmos, and to a lesser degree, in the icy atmospheres of some gas giants like Jupiter, on the rocky surfaces of meteorites, or in the exosphere of the Moon.
Its greatest concentration, however, lies in the novae or supernovae distributed throughout the Universe; as well as in the stars from which they originate, more voluminous than our sun, inside which neon atoms are produced as a result of a nucleosynthesis between carbon and oxygen.
Although its concentration is only 18.2 ppm in our air, it is enough to obtain a few liters of neon from any home space.
Thus, to produce it, it is necessary to liquefy the air and then carry out a cryogenic fractional distillation. In this way, its atoms can be separated from the liquid phase composed of liquid oxygen and nitrogen..
The most stable isotope of neon is twentyNe, with an abundance of 90.48%. It also has two other isotopes that are also stable, but less abundant: twenty-oneNe (0.27%) and 22Ne (9.25%). The rest are radioisotopes, and at the moment fifteen of them are known in total (15-19Ne and Ne23-32).
Neon is a harmless gas from almost every possible aspect. Due to its null chemical reactivity, it does not intervene at all with any metabolic process, and just as it enters the body, it leaves it without being assimilated. It therefore does not have an immediate pharmacological effect; although, it has been associated with possible anesthetic effects.
That is why if there is a neon leak, it is not a worrying alarm. However, if the concentration of its atoms in the air is very high, it can displace the oxygen molecules we breathe, which ends up causing suffocation and a series of symptoms associated with it..
However, liquid neon could cause cold burns on contact, so it is not advisable to touch it directly. Also, if the pressure in your containers is very high, an abrupt fissure could be explosive; not by the presence of flames but by the force of the gas.
Neon does not represent a danger to the ecosystem either. In addition, its concentration in the air is very low and there is no problem in breathing it. And most importantly: it is not a flammable gas. Therefore, it will never burn no matter how high the temperatures are..
As mentioned, red neon lights are present in thousands of establishments. The reason is that only a low gas pressure is required (~ 1/100 atm) so that it can produce, upon electric discharge, its characteristic light, which has also been placed in advertisements of different kinds (advertising, signs of road, etc.).
Neon-filled tubes can be made of glass or plastic, and can take on all kinds of shapes or forms..
Neon is a very important gas in the electronics industry. It is used for the manufacture of fluorescent and heating lamps; devices that detect radiation or high voltages, television kinescopes, Geyser counters, and ionization chambers.
Together with helium, the Ne-He duo can be used for laser devices, which project a beam of reddish light.
While it is true that neon cannot form any compounds, it has been found that under high pressures (~ 0.4 GPa) its atoms are trapped within the ice to form a clathrate. In it, the Ne atoms are confined to a kind of channel limited by water molecules, and within which they can move along the crystal.
Although at the moment there are not many potential applications for this neon clathrate, it could in the future be an alternative for its storage; or simply, serve as a model to deepen the understanding of these frozen materials. Perhaps, on some planets, neon is trapped in masses of ice.
Yet No Comments