Helium


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Chemistry in its element: helium

Most helium on Earth is a result of radioactive decay. In this way an estimated metric tons of helium are generated per year throughout the lithosphere. In seawater, the concentration is only 4 parts per trillion. There are also small amounts in mineral springs , volcanic gas, and meteoric iron. Because helium is trapped in the subsurface under conditions that also trap natural gas, the greatest natural concentrations of helium on the planet are found in natural gas, from which most commercial helium is extracted.

The resulting crude helium gas is purified by successive exposures to lowering temperatures, in which almost all of the remaining nitrogen and other gases are precipitated out of the gaseous mixture. Activated charcoal is used as a final purification step, usually resulting in In a final production step, most of the helium that is produced is liquefied via a cryogenic process. This is necessary for applications requiring liquid helium and also allows helium suppliers to reduce the cost of long distance transportation, as the largest liquid helium containers have more than five times the capacity of the largest gaseous helium tube trailers.

In the United States, most helium is extracted from natural gas of the Hugoton and nearby gas fields in Kansas, Oklahoma, and the Panhandle Field in Texas. Diffusion of crude natural gas through special semipermeable membranes and other barriers is another method to recover and purify helium. Helium must be extracted from natural gas because it is present in air at only a fraction of that of neon, yet the demand for it is far higher.

It is estimated that if all neon production were retooled to save helium, 0. Helium is commercially available in either liquid or gaseous form. According to helium conservationists like Nobel laureate physicist Robert Coleman Richardson , writing in , the free market price of helium has contributed to "wasteful" usage e.

Prices in the s had been lowered by the decision of the U. Congress to sell off the country's large helium stockpile by Estimated U. Total use is 34 million cubic meters. While balloons are perhaps the best known use of helium, they are a minor part of all helium use. Other uses by category were relatively minor fractions. Helium is used as a protective gas in growing silicon and germanium crystals, in titanium and zirconium production, and in gas chromatography , [81] because it is inert.

Because of its inertness, thermally and calorically perfect nature, high speed of sound , and high value of the heat capacity ratio , it is also useful in supersonic wind tunnels [] and impulse facilities. Helium is used as a shielding gas in arc welding processes on materials that at welding temperatures are contaminated and weakened by air or nitrogen. One industrial application for helium is leak detection.

Because helium diffuses through solids three times faster than air, it is used as a tracer gas to detect leaks in high-vacuum equipment such as cryogenic tanks and high-pressure containers. The measurement procedure is normally automatic and is called helium integral test. A simpler procedure is to fill the tested object with helium and to manually search for leaks with a hand-held device. Helium leaks through cracks should not be confused with gas permeation through a bulk material. While helium has documented permeation constants thus a calculable permeation rate through glasses, ceramics, and synthetic materials, inert gases such as helium will not permeate most bulk metals.

Because it is lighter than air , airships and balloons are inflated with helium for lift. While hydrogen gas is more buoyant, and escapes permeating through a membrane at a lower rate, helium has the advantage of being non-flammable, and indeed fire-retardant. Another minor use is in rocketry , where helium is used as an ullage medium to displace fuel and oxidizers in storage tanks and to condense hydrogen and oxygen to make rocket fuel. It is also used to purge fuel and oxidizer from ground support equipment prior to launch and to pre-cool liquid hydrogen in space vehicles.

Helium as a breathing gas has no narcotic properties , so helium mixtures such as trimix , heliox and heliair are used for deep diving to reduce the effects of narcosis, which worsen with increasing depth. This reduces the Reynolds number of flow, leading to a reduction of turbulent flow and an increase in laminar flow , which requires less work of breathing.

Helium—neon lasers , a type of low-powered gas laser producing a red beam, had various practical applications which included barcode readers and laser pointers , before they were almost universally replaced by cheaper diode lasers. For its inertness and high thermal conductivity , neutron transparency, and because it does not form radioactive isotopes under reactor conditions, helium is used as a heat-transfer medium in some gas-cooled nuclear reactors. Helium, mixed with a heavier gas such as xenon, is useful for thermoacoustic refrigeration due to the resulting high heat capacity ratio and low Prandtl number.

Helium is also used in some hard disk drives. The use of helium reduces the distorting effects of temperature variations in the space between lenses in some telescopes , due to its extremely low index of refraction. Helium is a commonly used carrier gas for gas chromatography. The age of rocks and minerals that contain uranium and thorium can be estimated by measuring the level of helium with a process known as helium dating.

Helium at low temperatures is used in cryogenics , and in certain cryogenics applications. As examples of applications, liquid helium is used to cool certain metals to the extremely low temperatures required for superconductivity , such as in superconducting magnets for magnetic resonance imaging. While chemically inert, helium contamination will impair the operation of microelectromechanical systems such that iPhones may fail. Neutral helium at standard conditions is non-toxic, plays no biological role and is found in trace amounts in human blood.

The speed of sound in helium is nearly three times the speed of sound in air. Because the fundamental frequency of a gas-filled cavity is proportional to the speed of sound in the gas, when helium is inhaled there is a corresponding increase in the resonant frequencies of the vocal tract. The opposite effect, lowering resonant frequencies, can be obtained by inhaling a dense gas such as sulfur hexafluoride or xenon.

Inhaling helium can be dangerous if done to excess, since helium is a simple asphyxiant and so displaces oxygen needed for normal respiration. Death caused by helium is rare. The first media-recorded case was that of a year-old girl from Texas who died in from helium inhalation at a friend's party; the exact type of helium death is unidentified. In the United States only two fatalities were reported between and , including a man who died in North Carolina of barotrauma in On February 4, it was revealed that during the recording of their main TV show on January 28, a year-old member name withheld of Japanese all-girl singing group 3B Junior suffered from air embolism , losing consciousness and falling in a coma as a result of air bubbles blocking the flow of blood to the brain, after inhaling huge quantities of helium as part of a game.

The incident was not made public until a week later. Police have launched an investigation due to a neglect of safety measures. Smith , "apparently" committed suicide in May at a hotel room in Rochester, Minnesota and that his death was recorded as "asphyxiation due to displacement of oxygen in confined space with helium". The safety issues for cryogenic helium are similar to those of liquid nitrogen ; its extremely low temperatures can result in cold burns , and the liquid-to-gas expansion ratio can cause explosions if no pressure-relief devices are installed.

Containers of helium gas at 5 to 10 K should be handled as if they contain liquid helium due to the rapid and significant thermal expansion that occurs when helium gas at less than 10 K is warmed to room temperature. From Wikipedia, the free encyclopedia. This article is about the chemical element. For other uses, see Helium disambiguation. Chemical element with atomic number 2. Main article: Helium atom.

Main article: Liquid helium. Main article: Superfluid helium Main article: Isotopes of helium. Main article: Helium compounds. Main article: Helium storage and conservation. Main article: Gas tungsten arc welding. Effect of helium on a human voice. Abiogenic petroleum origin Helium-3 propulsion Leidenfrost effect Quantum solid Superfluid Tracer-gas leak testing method Hamilton Cady. Pure and Applied Chemistry. Lein, Daniel A. Morgan Kirk Othmer Encyclopedia of Chemical Technology.


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From p. I saw immediately a series of nine bright lines that Biman B.

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Nevertheless, Lockyer quoted from his report. Norman "The story of helium. I am not prepared to offer any explanation of this. Wheeler M. The bright yellow line did indeed lie very close to D, but the light was more refrangible [i. My subsequent studies of the Sun have shown the accuracy of what I state here.

Photonics Spectra. Retrieved February 27, For a more authoritative but older pie chart showing U. The Independent. Retrieved Starts with a Bang. The Guardian. Journal of the British Astronomical Association. Bibcode : JBAA.. Nature's Building Blocks. Oxford: Oxford University Press. October Proceedings of the Royal Society of London. Bibcode : RSPS Retrieved 3 June The Encyclopedia of the Chemical Elements. New York: Van Nostrand Reinhold. Online Etymology Dictionary. Bibcode : Natur Frankland and Lockyer find the yellow prominences to give a very decided bright line not far from D, but hitherto not identified with any terrestrial flame.

Retrieved 1 May Raccolsi alcun tempo fa una sostanza amorfa di consistenza butirracea e di colore giallo sbiadato sublimata sull'orlo di una fumarola prossima alla bocca di eruzione. Do per ora il semplice annunzio del fatto, proponendomi di ritornare sopra questo argomento, dopo di aver sottoposta la sublimazione ad una analisi chimica. I collected some time ago an amorphous substance having a buttery consistency and a faded yellow color which had sublimated on the rim of a fumarole near the mouth of the eruption. Having analyzed this sublimated substance with a spectroscope, I recognized the lines of sodium and potassium and a very distinct linear line which corresponds exactly to D 3 , which is that of helium.

For the present, I'm making a mere announcement of the fact, proposing to return to this subject after having subjected the sublimate to a chemical analysis. University College London. Retrieved 18 August Preliminary Note". Part I". Part II — Density". Norman Preliminary note, part II". Geological Survey , no. John A. Garraty; Mark C. Carnes eds.

Humanity Is Thoughtlessly Wasting An Essential, Non-Renewable Resource: Helium

Biographical entry for W. Hillebrand — , geochemist and U. Bureau of Standards administrator in American National Biography. Oxford University Press. Spectrum of the radium emanation". Philosophical Magazine. Physics Today. Bibcode : PhT Archived from the original PDF on June 25, Preliminary notice: Keesom, W.


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