Neon was discovered in June 1898 by the British chemists William Ramsay and Morris William Travers at University College London. The pair isolated the new element by carefully separating liquid air into its component gases, a process that also yielded krypton and xenon within the same remarkable year. The story of neon’s discovery is really the story of a deliberate, methodical hunt for an entire family of elements that the periodic table predicted should exist but that nobody had yet found.
The Problem That Started the Hunt
To understand why Ramsay and Travers were sifting through liquid air in the first place, you need to know about argon. In 1894, Ramsay and the physicist Lord Rayleigh had announced the discovery of argon, a gas that made up about one percent of the atmosphere yet had somehow escaped detection for over a century. Argon was strange: it refused to react with anything. No known acid, base, or metal could coax it into forming a compound. That chemical inertness made it invisible to the standard analytical tools of the day, which relied on reactions to identify substances.
Argon’s discovery raised an obvious question. If one completely unreactive gas had been hiding in plain sight, could there be others? Ramsay thought so. The periodic table, as it existed in the late 1890s, hinted at gaps where undiscovered elements might sit. Ramsay suspected that argon belonged to an entirely new group of elements, and he set about searching for its relatives. The discovery of helium in terrestrial minerals in 1895 confirmed his suspicion that this was a family, not a lone oddity. By 1898, Ramsay had both the theoretical motivation and the practical tools to go looking for more members of the group.
How Ramsay and Travers Found Neon
The key technology was fractional distillation of liquid air. Air is a mixture of gases, and each gas has a different boiling point. If you cool air until it liquefies and then slowly warm it back up, the gases boil off one by one, lightest and lowest-boiling-point first. By collecting the gas that comes off at each temperature stage, you can separate air into its individual components. In the spring of 1898, Ramsay and Travers obtained a large quantity of liquid air and began this painstaking separation process.
Their first success came in May 1898, when spectral analysis of the least volatile fraction of liquid air revealed a new element they named krypton (from the Greek for “hidden”). But Ramsay was not satisfied. He reasoned that if a heavier-than-argon gas existed in air, a lighter-than-argon gas might as well. So the pair turned their attention to the argon fraction itself, looking for a component with a lower boiling point that might be hiding within it. They collected the gas that boiled off from liquid argon before argon itself did, and in June 1898 they examined it with a spectroscope.
What they saw was unmistakable. When an electric current was passed through a glass tube containing the new gas, it emitted a brilliant crimson-orange glow and produced a set of spectral lines that matched no known element. The discovery of krypton and neon was announced to the Royal Society in the early summer of 1898.1Proceedings of the Royal Society of London. Argon and its companions Travers later recalled that the vivid glow was so striking that Ramsay reportedly said, “It is neon,” almost immediately, so confident was he that this was the new element they had been hunting.
Why They Called It Neon
Ramsay chose the name “neon” from the Greek word neos, meaning “new.” The name was suggested by Ramsay’s thirteen-year-old son, who initially proposed “novum,” the Latin equivalent. Ramsay liked the idea but preferred the Greek form, which was more consistent with the naming conventions used for other elements. It was a straightforward, almost understated name for a gas that would eventually become synonymous with bright, colorful light. In a nice bit of irony, the element named “new” is now one of the most abundant elements in the universe.
The names of the other noble gases discovered around the same time follow a similar pattern of Greek roots. Krypton means “hidden,” xenon means “strange,” and argon means “idle” or “lazy,” a reference to its chemical inertness. The naming choices reflected the personality of each discovery: argon was the stubborn gas that would not react, krypton was the gas that had been hiding in plain sight, and neon was simply the newest addition to the family.
A Remarkable Year for the Noble Gases
The speed of the 1898 discoveries is worth appreciating. Ramsay and Travers found krypton in May, neon in June, and xenon in July. Three new elements in roughly twelve weeks, all pulled from the same supply of liquid air using the same basic technique of fractional distillation.2The Chemical Educator. Krypton, Neon and Xenon – Their Discoveries This was not a lucky accident repeated three times. It was a systematic campaign. Ramsay knew what he was looking for, had a clear theoretical framework for why these elements should exist, and had perfected the laboratory skills needed to find them.
The work earned Ramsay the Nobel Prize in Chemistry in 1904, awarded for his discovery of the inert gaseous elements in air and his determination of their place in the periodic table. Travers, despite being Ramsay’s hands-on partner in the laboratory for all three discoveries, did not share the Nobel. This was partly a reflection of the era’s conventions around credit: Ramsay was the senior professor, and Travers was a younger assistant. Travers went on to a distinguished career of his own, including a stint as director of the Indian Institute of Science in Bangalore, but history has generally given Ramsay the larger share of recognition for the noble gas discoveries.
Neon’s Most Famous Trick
The vivid reddish-orange glow that Ramsay and Travers observed in their laboratory tube was not just a diagnostic tool for identification. It turned out to be neon’s defining practical feature. When neon gas is sealed inside a glass tube and an electrical voltage is applied, the gas emits light far more efficiently than an incandescent filament, and the color is remarkably stable over time.
Georges Claude, a French engineer and inventor, demonstrated the first neon lamp publicly in Paris in December 1910. By the early 1920s, neon signs had arrived in the United States, and within a decade they had transformed the visual landscape of commercial districts from Times Square to the Las Vegas Strip. The term “neon sign” became so ubiquitous that it is now used loosely to describe any gas-discharge tube sign, even though many of those signs use other gases. True neon produces only a reddish-orange color. The blues, greens, purples, and whites of other “neon” signs come from argon, mercury vapor, phosphor coatings on the inside of the glass, or combinations of these.
This distinction matters if you are ever shopping for a sign or trying to understand why vintage neon has a particular warm quality that modern LED replacements struggle to replicate. The glow of genuine neon is produced by individual atoms returning to their resting energy state after being excited by the electrical discharge, and each wavelength of light corresponds to a specific energy transition. The result is a spectrum that the human eye perceives as rich and warm rather than flat. LED substitutes approximate the color but not the spectral character, which is why neon purists and sign collectors remain loyal to the real thing.
How Rare Is Neon on Earth
Neon is one of the most abundant elements in the cosmos, ranking fifth by mass in the universe after hydrogen, helium, oxygen, and carbon. On Earth, though, it is scarce. The atmosphere contains only about 18 parts per million of neon by volume, which makes it roughly a thousand times less abundant than argon in the air you breathe. Earth’s gravity is too weak to hold onto such a light, unreactive gas over geological timescales, so most of the neon that was present when the planet formed has escaped into space.
The neon that remains in the atmosphere is the sole commercial source of the gas. It is extracted as a by-product of cryogenic air separation, the same basic process Ramsay and Travers used, scaled up to industrial proportions.3Sustainable Energy Technologies and Assessments. Proposal and investigation of a novel process configuration for production of neon from cryogenic air separation unit Large air separation plants cool air to around minus 200 degrees Celsius, liquefy it, and then distill it into oxygen, nitrogen, argon, and trace gases including neon. Because neon is present in such small concentrations, producing even modest quantities requires processing enormous volumes of air, which is one reason the gas has historically been expensive relative to more common industrial gases.
This supply chain became front-page news in 2022, when geopolitical disruptions threatened neon supplies from major production facilities in Eastern Europe. The semiconductor industry is a significant consumer of high-purity neon, which is used in the excimer lasers that etch circuit patterns onto silicon chips. Suddenly, a gas that most people associated only with bar signs turned out to be a critical input for the global electronics supply chain. The episode prompted chipmakers and gas suppliers to diversify their sourcing, but it also highlighted how dependent modern technology is on a handful of trace atmospheric gases that few people think about.
Neon in Stars and Deep Inside Earth
Neon is forged inside massive stars through nuclear fusion. In the late stages of a heavy star’s life, after it has burned through its hydrogen and helium fuel, the core temperature rises high enough for carbon and oxygen nuclei to fuse into heavier elements including neon, magnesium, and silicon. Neon itself can serve as fuel in a subsequent burning phase. Three-dimensional simulations of neon-burning convective shells in stars around fifteen times the mass of the sun show that these burning zones are relatively compact and short-lived, persisting for weeks to months before the star moves on to even heavier fuel cycles on its way toward a supernova.4Oxford Academic. 3D simulations of a neon burning convective shell in a massive star When that supernova finally occurs, the neon synthesized in the star’s interior is blasted into the interstellar medium, where it eventually becomes part of the raw material for new stars and planets.
Some of that primordial neon ended up inside Earth, trapped in the planet’s deep mantle during formation. Geochemists study the isotopic ratios of neon in volcanic gases and deep well gases to learn about the origins of Earth’s volatile elements. Research on neon isotopes in the convecting mantle has shown that the pattern is consistent with solar corpuscular irradiation of the material that accreted to form Earth, rather than equilibration with a thick early atmosphere captured directly from the solar nebula.5PubMed. Neon isotopes constrain convection and volatile origin in the Earth’s mantle In plain terms, the neon locked deep inside our planet seems to have arrived embedded in small grains of cosmic dust and rock rather than being grabbed from a blanket of gas around the young sun. Neon isotope measurements have become a surprisingly powerful tool for reconstructing how Earth was built billions of years ago.
Why Neon Took So Long to Find
Given that neon is the fifth most abundant element in the universe, you might wonder why it was not discovered until 1898, decades after dozens of far rarer elements had already been catalogued. The answer lies in the combination of traits that define the noble gases: chemical inertness and low terrestrial abundance. The classical methods of analytical chemistry depended on reactions. You identified an element by what it combined with, what precipitate it formed, what color it turned a flame. Neon does none of these things. It does not burn, dissolve, corrode, or bond with other atoms under normal conditions. It is, for all practical chemical purposes, invisible to reaction-based analysis.
The only tool that could reveal neon was the spectroscope, which identifies elements by the unique pattern of light they emit when energized. But spectroscopy required a pure or nearly pure sample of the gas, and isolating neon from air required liquefaction technology that simply did not exist before the 1890s. The ability to liquefy air at industrial scale was a breakthrough of late-nineteenth-century physics and engineering. Without it, there was no way to separate neon from the overwhelming bulk of nitrogen and oxygen in the atmosphere. Ramsay and Travers were working at the cutting edge of cryogenic technology for their time, and the sequence in which they found the noble gases tracked directly with the order in which those gases boiled out of liquid air.
Neon’s Chemical Stubbornness
Among the noble gases, neon stands out as the most resistant to forming chemical bonds. Helium shares this extreme reluctance, but the heavier noble gases have been coaxed into compounds under special conditions. Xenon, for example, was shown to form stable compounds with fluorine in the early 1960s, and krypton difluoride has also been synthesized. Argon compounds have been produced under extreme laboratory conditions. Even radon, the radioactive member of the family, is expected to form compounds more readily than neon.
Neon, however, has resisted all attempts. No stable neutral neon compound has been confirmed under any conditions, and theoretical calculations suggest that the energy required to force neon into a bond is prohibitively high. Its electron configuration is so tightly held and so perfectly symmetrical that other atoms have essentially nothing to offer it energetically. This makes neon the textbook example of a completely unreactive element, even more so than helium in certain contexts because neon has a larger electron shell and yet still refuses to participate in chemistry. Researchers have explored whether extreme pressures or electric fields might change this, but so far neon remains the holdout, the element that truly wants to be left alone.
This stubbornness has practical value beyond just being a curiosity. In industrial and scientific applications where contamination from chemical reactions would be disastrous, neon’s inertness is an asset. It serves as a cryogenic refrigerant in certain physics experiments, partly because it liquefies at a very low temperature (about minus 246 degrees Celsius, only a few degrees above liquid hydrogen) and partly because it will not react with anything in the apparatus. For high-voltage equipment, neon’s predictable and stable discharge behavior makes it useful in voltage indicators, lightning arrestors, and plasma displays. The same property that made neon invisible to nineteenth-century chemists is what makes it valuable to twenty-first-century engineers.