Product Code Database
Neon is a chemical element; it has symbol Ne and atomic number 10. It is the second noble gas in the periodic table.Group 18 refers to the modern numbering of the periodic table. Older numberings described the rare gases as Group 0 or Group VIIIA (sometimes shortened to 8). See also Group (periodic table). Neon is a colorless, odorless, inert monatomic gas under standard conditions, with approximately two-thirds the density of air.
Neon was discovered in 1898 alongside krypton and xenon, identified as one of the three remaining rare inert elements in dry air after the removal of nitrogen, oxygen, argon, and carbon dioxide. Its discovery was marked by the distinctive bright red emission spectrum it exhibited, leading to its immediate recognition as a new element. The name neon originates from the Greek word νέον, a neuter singular form of νέος (), meaning 'new'. Neon is a chemically inert gas; although neon compounds do exist, they are primarily ionic molecules or fragile molecules held together by van der Waals forces.
The synthesis of most neon in the cosmos resulted from the nuclear fusion within stars of oxygen and helium through the Alpha process. Despite its abundant presence in the universe and Solar System—ranking fifth in cosmic abundance following hydrogen, helium, oxygen, and carbon—neon is comparatively scarce on Earth. It constitutes about 18.2 ppm of Earth's atmospheric volume and a lesser fraction in the Earth's crust. The high volatility of neon and its inability to form compounds that would anchor it to solids explain its limited presence on Earth and the Inner planets. Neon’s high volatility facilitated its escape from under the early Solar System's nascent Sun's warmth.
Neon's notable applications include its use in low-voltage neon glow lamps, Geissler tube, and Neon sign, where it emits a distinct reddish-orange glow. This same red emission line is responsible for the characteristic red light of helium–neon lasers. Although neon has some applications in plasma tubes and as a refrigerant, its commercial uses are relatively limited. It is primarily obtained through the fractional distillation of liquid air, making it significantly more expensive than helium due to air being its sole source.
A second gas was also reported along with neon, having approximately the same density as argon but with a different spectrum – Ramsay and Travers named it metargon.
Neon's scarcity precluded its prompt application for lighting along the lines of , which used nitrogen and which were commercialized in the early 1900s. After 1902, Georges Claude's company Air Liquide produced industrial quantities of neon as a byproduct of his air-liquefaction business. In December 1910 Claude demonstrated modern neon lighting based on a sealed tube of neon. Claude tried briefly to sell neon tubes for indoor domestic lighting, due to their intensity, but the market failed because homeowners objected to the color. In 1912, Claude's associate began selling neon discharge tubes as eye-catching neon sign and was instantly more successful. Neon tubes were introduced to the U.S. in 1923 with two large neon signs bought by a Los Angeles Packard car dealership. The glow and arresting red color made neon advertising completely different from the competition. The intense color and vibrancy of neon equated with American society at the time, suggesting a "century of progress" and transforming cities into sensational new environments filled with radiating advertisements and "electro-graphic architecture".
Neon played a role in the basic understanding of the nature of atoms in 1913, when J. J. Thomson, as part of his exploration into the composition of canal rays, channeled streams of neon ions through a magnetic and an electric field and measured the deflection of the streams with a photographic plate. Thomson observed two separate patches of light on the photographic plate (see image), which suggested two different parabolas of deflection. Thomson eventually concluded that some of the in the neon gas were of higher mass than the rest. Though not understood at the time by Thomson, this was the first discovery of of Stable isotope atoms. Thomson's device was a crude version of the instrument we now term a mass spectrometer.
The principal generating nucleogenic neon start from 24Mg and 25Mg, which produce 21Ne and 22Ne respectively, after neutron capture and immediate emission of an alpha particle. The that produce the reactions are mostly produced by secondary spallation reactions from alpha particles, in turn derived from uranium-series . The net result yields a trend towards lower 20Ne/22Ne and higher 21Ne/22Ne ratios observed in uranium-rich rocks such as . Resources on Isotopes Periodic Table—Neon at the U.S. Geological Survey, by Eric Caldwell, posted January 2004, retrieved 10 February 2011
In addition, isotopic analysis of exposed terrestrial rocks has demonstrated the cosmogenic (cosmic ray) production of 21Ne. This isotope is generated by spallation reactions on magnesium, sodium, silicon, and aluminium. By analyzing all three isotopes, the cosmogenic component can be resolved from neon and nucleogenic neon. This suggests that neon will be a useful tool in determining cosmic exposure ages of surface rocks and .
Neon in solar wind contains a higher proportion of 20Ne than nucleogenic and cosmogenic sources. Neon content observed in samples of volcano and is also enriched in 20Ne, suggesting a primordial, possibly solar origin.
Neon plasma has the most intense light discharge at normal voltages and currents of all the noble gases. The average color of this light to the human eye is red-orange due to many lines in this range; it also contains a strong green line, which is hidden, unless the visual components are dispersed by a spectroscope.
Neon is abundant on a universal scale; it is the fifth most abundant chemical element in the universe by mass, after hydrogen, helium, oxygen, and carbon (see chemical element). Its relative rarity on Earth, like that of helium, is due to its relative lightness, high vapor pressure at very low temperatures, and chemical inertness, all properties which tend to keep it from being trapped in the condensing gas and dust clouds that formed the smaller and warmer solid planets like Earth. Neon is monatomic, making it lighter than the molecules of diatomic nitrogen and oxygen which form the bulk of Earth's atmosphere; a balloon filled with neon will rise in air, albeit more slowly than a helium balloon.
Neon's abundance in the universe is about 1 part in 750 by mass; in the Sun and presumably in its proto-solar system nebula, about 1 part in 600. The Galileo spacecraft atmospheric entry probe found that in the upper atmosphere of Jupiter, the abundance of neon is reduced (depleted) by about a factor of 10, to a level of 1 part in 6,000 by mass. This may indicate that the ice- that brought neon into Jupiter from the outer solar system formed in a region that was too warm to retain the neon atmospheric component (abundances of heavier inert gases on Jupiter are several times that found in the Sun), or that neon is selectively sequestered in the planet's interior.
Neon comprises 1 part in 55,000 in the Earth's atmosphere, or 18.2 ppm by volume (this is about the same as the molecule or mole fraction), or 1 part in 79,000 of air by mass. It comprises a smaller fraction in the crust. It is industrially produced by cryogenic fractional distillation of liquefied air.
On 17 August 2015, based on studies with the Lunar Atmosphere and Dust Environment Explorer (LADEE) spacecraft, NASA scientists reported the detection of neon in the exosphere of the moon.
The familiar Pauling electronegativity scale relies upon chemical bond energies, but such values have obviously not been measured for inert helium and neon. The Allen electronegativity scale, which relies only upon (measurable) atomic energies, identifies neon as the most electronegative element, closely followed by fluorine and helium.
The triple point temperature of neon (24.5561 K) is a defining fixed point in the International Temperature Scale of 1990.
Before the 2022 escalation of the war with Russia about 70% of the global neon supply was produced in Ukraine as a by-product of steel production in Russia. , the company Iceblick, with plants in Odesa and Moscow, supplies 65% of the world's production of neon, as well as 15% of the krypton and xenon.
In , neon produces an unmistakable bright reddish-orange light when electric current passes through it under low pressure. Although tube lights with other colors are often called "neon", they use different or varied colors of Fluorescent bulb lighting, for example, argon produces a lavender or blue hue. As of 2012, there are over one hundred colors available.
Liquefied neon is commercially used as a cryogenic refrigerant in applications not requiring the lower temperature range attainable with the more extreme liquid helium refrigeration.
|
|
