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- Helium abstract "Helium is a chemical element with symbol He and atomic number 2. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas that heads the noble gas group in the periodic table. Its boiling and melting points are the lowest among the elements and it exists only as a gas except in extreme conditions.Helium is the second lightest element and is the second most abundant element in the observable universe, being present at about 24% of the total elemental mass, which is more than 12 times the mass of all the heavier elements combined. Its abundance is similar to this figure in the Sun and in Jupiter. This is due to the very high nuclear binding energy (per nucleon) of helium-4 with respect to the next three elements after helium. This helium-4 binding energy also accounts for why it is a product of both nuclear fusion and radioactive decay. Most helium in the universe is helium-4, and is believed to have been formed during the Big Bang. Large amounts of new helium are being created by nuclear fusion of hydrogen in stars.Helium is named for the Greek god of the Sun, Helios. It was first detected as an unknown yellow spectral line signature in sunlight during a solar eclipse in 1868 by French astronomer Jules Janssen. Janssen is jointly credited with detecting the element along with Norman Lockyer. Jannsen observed during the solar eclipse of 1868 while Lockyer observed from Britain. Lockyer was the first to propose that the line was due to a new element, which he named. The formal discovery of the element was made in 1895 by two Swedish chemists, Per Teodor Cleve and Nils Abraham Langlet, who found helium emanating from the uranium ore cleveite. In 1903, large reserves of helium were found in natural gas fields in parts of the United States, which is by far the largest supplier of the gas today.Helium is used in cryogenics (its largest single use, absorbing about a quarter of production), particularly in the cooling of superconducting magnets, with the main commercial application being in MRI scanners. Helium's other industrial uses—as a pressurizing and purge gas, as a protective atmosphere for arc welding and in processes such as growing crystals to make silicon wafers—account for half of the gas produced. A well-known but minor use is as a lifting gas in balloons and airships. As with any gas whose density differs from that of air, inhaling a small volume of helium temporarily changes the timbre and quality of the human voice. In scientific research, the behavior of the two fluid phases of helium-4 (helium I and helium II) is important to researchers studying quantum mechanics (in particular the property of superfluidity) and to those looking at the phenomena, such as superconductivity, produced in matter near absolute zero.On Earth it is relatively rare — 5.2 ppm by volume in the atmosphere. Most terrestrial helium present today is created by the natural radioactive decay of heavy radioactive elements (thorium and uranium, although there are other examples), as the alpha particles emitted by such decays consist of helium-4 nuclei. This radiogenic helium is trapped with natural gas in concentrations up to 7% by volume, from which it is extracted commercially by a low-temperature separation process called fractional distillation. Helium is a finite resource and is one of the only elements with escape velocity, meaning that once released into the atmosphere, it escapes into space.".
- Helium thumbnail Helium_spectrum.jpg?width=300.
- Helium wikiPageExternalLink helium.html.
- Helium wikiPageExternalLink ele002.html.
- Helium wikiPageExternalLink Helium_Shortages_Chan-Richardson.pdf.
- Helium wikiPageExternalLink helium.
- Helium wikiPageExternalLink heliumcs07.pdf.
- Helium wikiPageExternalLink mcs-2012-heliu.pdf.
- Helium wikiPageExternalLink gpo35149.
- Helium wikiPageExternalLink gpo41438.
- Helium wikiPageExternalLink Thermotxt.en.html.
- Helium wikiPageExternalLink BEF74B49AFC3099DC1257A2200473157.
- Helium wikiPageExternalLink NR0701_2.html.
- Helium wikiPageExternalLink neng0603.html.
- Helium wikiPageExternalLink helium.htm.
- Helium wikiPageExternalLink 002.htm.
- Helium wikiPageExternalLink speech.html.
- Helium wikiPageExternalLink index.htm.
- Helium wikiPageExternalLink senate_bill_would_preserve_us_helium_reserve.
- Helium wikiPageExternalLink element.asp.
- Helium wikiPageExternalLink CIIE_Helium_48kbps_tcm18-133173.mp3.
- Helium wikiPageID "13256".
- Helium wikiPageRevisionID "604119597".
- Helium b "y".
- Helium bSearch "Wikijunior:The Elements/Helium".
- Helium book "Chemical elements".
- Helium book "Helium".
- Helium book "Noble gases".
- Helium book "Period 1 elements".
- Helium commons "y".
- Helium description "The effect of helium on a human voice".
- Helium filename "Helium article read with helium.ogg".
- Helium format Ogg.
- Helium hasPhotoCollection Helium.
- Helium portal "Chemistry".
- Helium title "Effect of helium on a human voice".
- Helium v "y".
- Helium vSearch "Helium atom".
- Helium wikt "y".
- Helium subject Category:Airship_technology.
- Helium subject Category:Chemical_elements.
- Helium subject Category:Coolants.
- Helium subject Category:Diving_equipment.
- Helium subject Category:Helium.
- Helium subject Category:Noble_gases.
- Helium subject Category:Nuclear_reactor_coolants.
- Helium comment "Helium is a chemical element with symbol He and atomic number 2. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas that heads the noble gas group in the periodic table.".
- Helium label "Elio".
- Helium label "Hel (pierwiastek)".
- Helium label "Helio".
- Helium label "Helium".
- Helium label "Helium".
- Helium label "Helium".
- Helium label "Hélio".
- Helium label "Hélium".
- Helium label "Гелий".
- Helium label "هيليوم".
- Helium label "ヘリウム".
- Helium label "氦".
- Helium sameAs Helium.
- Helium sameAs Helium.
- Helium sameAs Ήλιο.
- Helium sameAs Helio.
- Helium sameAs Helio.
- Helium sameAs Hélium.
- Helium sameAs Helium.
- Helium sameAs Elio.
- Helium sameAs ヘリウム.
- Helium sameAs 헬륨.
- Helium sameAs Helium.
- Helium sameAs Hel_(pierwiastek).
- Helium sameAs Hélio.
- Helium sameAs m.025rt79.
- Helium sameAs Q560.
- Helium sameAs Q560.
- Helium wasDerivedFrom Helium?oldid=604119597.
- Helium depiction Helium_spectrum.jpg.
- Helium isPrimaryTopicOf Helium.