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Topic: Helium


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In the News (Mon 20 Nov 17)

  
  Helium - MSN Encarta
Helium is used in inert-gas arc welding for light metals such as aluminum and magnesium alloys that might otherwise oxidize; the helium protects heated parts from attack by air.
Helium is used in place of nitrogen as part of the synthetic atmosphere breathed by deep-sea divers, caisson workers, and others, because it reduces susceptibility to the bends.
Helium, which may be essential to future advanced technologies, was not stockpiled by the U.S. government between 1973 and 1980, nor were private natural-gas producers required to recover helium from their wells.
encarta.msn.com /encyclopedia_761562418/Helium.html   (920 words)

  
 Helium - Wikipedia, the free encyclopedia
Helium is used in cryogenics, as a deep-sea breathing gas, for inflating balloons and airships, and as a protective gas for many industrial purposes, such as arc welding.
Evidence of helium was first detected on August 18, 1868 as a bright yellow line with a wavelength of 587.49 nanometres in the spectrum of the chromosphere of the Sun, by French astronomer Pierre Janssen during a total solar eclipse in Guntur, India.
The principal impurity in Grade-A helium is neon.
en.wikipedia.org /wiki/Helium   (4522 words)

  
 Ensiklopedia :: encyclopedia : Helium   (Site not responding. Last check: 2007-10-22)
Helium merupakan gas nadir yang stabil pada jumlah kecil dan tidak boleh terbakar.
Helium lebih ringan daripada udara dan digunakan dalam kapal udara dan belon, menggantikan gas hidrogen untuk terapung di udara disebabkan oleh kemudahbakaran gas Hidrogen.
Helium juga dicampurkan dengan oksigen untuk pernafasan bagi penjelajahan laut dalam.
www.ensiklopedia.info /Helium   (196 words)

  
 [No title]   (Site not responding. Last check: 2007-10-22)
A colorless, odorless noble gas, helium has the lowest boiling point of any element and can only be solidified under great pressure.
Helium (Greek helios meaning "the sun") was discovered by Frenchman Pierre Janssen and Englishman Norman Lockyer working independently of each other in 1868.
Containers filled with gaseous helium at 5 to 10 K should be stored as if they contained liquid helium due to the large increase in pressure that results from warming the gas to room temperature.
wikiwhat.com /encyclopedia/h/he/helium.html   (1456 words)

  
 Helium   (Site not responding. Last check: 2007-10-22)
Helium has the lowest melting point of any element and has found wide use in cryogenic research as its boiling point is close to absolute zero.
Containers filled with helium gas at 5 to 10 K should be treated as though they contained liquid helium due to the large increase in pressure resulting from warming the gas to room temperature.
Helium is widely used as an inert gas shield for arc welding; as a protective gas in growing silicon and germanium crystals, and in titanium and zirconium production; as a cooling medium for nuclear reactors, and as a gas for supersonic wind tunnels.
www.scescape.net /~woods/elements/helium.html   (798 words)

  
 Helium dating - Wikipedia, the free encyclopedia
Helium Dating (or He dating) is the method of age determination that depends on the production of helium during the decay of the radioactive isotopes uranium-235 (U-235), uranium-238 (U-238), and thorium-232 (Th-232).
Because of this decay, the helium content of any mineral or rock capable of retaining helium will increase during the lifetime of that mineral or rock, and the ratio of helium to its radioactive progenitors then becomes a constant.
The helium content may be artificially lowered by improper handling of the specimen, as it may leak from the crystal lattice during grinding or other rough mechanical handling.
en.wikipedia.org /wiki/Helium_dating   (157 words)

  
 Helium
Helium is a close approximation to the hard-sphere gas studied in kinetic theory, and so is a good example of the theory.
Helium II is actually a many-particle system in which some of the atoms are in the superfluid ground state, while the remainder are in excited states, whose energies are functions of their momenta.
Helium and argon are used in welding to shield the hot metal from the atmosphere, especially in the case of reactive metals.
www.du.edu /~jcalvert/phys/helium.htm   (8914 words)

  
 CD015: Helium diffusion from zircons
The high helium concentration may be due to samples that were abnormally high in uranium and/or to the presence of excess helium.
If helium concentrations stay high around the rocks, it is possible for helium to diffuse into voids and fractures in the zircons, or at least high helium pressures could reduce the rate at which helium diffuses out.
Helium deposits are common in New Mexico, and excess helium has been found just a few miles from where the sample was taken (Goff and Gardner 1994).
www.talkorigins.org /indexcc/CD/CD015.html   (927 words)

  
 helium - The Columbia Encyclopedia, Sixth Edition - HighBeam Research   (Site not responding. Last check: 2007-10-22)
Helium was isolated (1895) from a sample of the uranium mineral cleveite by Sir William Ramsay.
Helium is less dense than any other known gas except hydrogen and is about one seventh as dense as air.
Some helium is extracted directly from the atmosphere; the gas is also found in certain uranium minerals and in some mineral waters, but not in economic quantities.
www.highbeam.com /doc/1E1:helium/helium.html?refid=ip_hf   (551 words)

  
 Helium   (Site not responding. Last check: 2007-10-22)
Helium, He, is a colourless gaseous non-metallic element which belong to Group 0 of the periodic table.
Helium was discovered from the spectroscopic examination of a gas which was occluded in certain minerals including cleveite (i.e.
Helium is present in the gaseous emissions from natural springs in the USA and it is also present (at 1% level) in natural gas in the USA.
www.ucc.ie /ucc/depts/chem/dolchem/html/elem/elem002.html   (235 words)

  
 CE001: Not Enough Helium?   (Site not responding. Last check: 2007-10-22)
Helium is a very light atom, and some of the helium in the upper atmosphere can reach escape velocity simply via its temperature.
Thermal escape of helium alone is not enough to account for its scarcity in the atmosphere, but helium in the atmosphere also gets ionized and follows the earth's magnetic field lines.
Helium escape from the terrestrial atmosphere - the ion outflow mechanism.
www.talkorigins.org /indexcc/CE/CE001.html   (143 words)

  
 APOD: 2001 January 20 - Helios Helium   (Site not responding. Last check: 2007-10-22)
Helium was first discovered in the Sun in 1868, its name fittingly derived from from the Greek word Helios, meaning Sun.
Helium bearing mineral of Uranium provided an exact match to the previously detected element of the Sun.
Helium is now known to be the second most abundant element (after Hydrogen) in the Universe.
antwrp.gsfc.nasa.gov /apod/ap010120.html   (158 words)

  
 SPACE.com -- Researchers and space enthusiasts see helium-3 as the perfect fuel source.
"Helium 3 could be the cash crop forthe moon," said Kulcinski, a longtime advocate and leading pioneer in thefield, who envisions the moon becoming "the Hudson Bay Store of Earth."Today helium 3 would have a cash value of $4 billion a ton in terms ofits energy equivalent in oil, he estimates.
Helium 3, an isotope of the familiarhelium used to inflate balloons and blimps, has a nucleus with two protonsand one neutron.
While it's true that to produce roughly70 tons of helium 3, for example, a million tons of lunar soil would needto be heated to 1,470 degrees Fahrenheit (800 degrees Celsius) to liberatethe gas, proponents say lunar strip mining is not the goal.
www.space.com /scienceastronomy/helium3_000630.html   (1141 words)

  
 It's Elemental - The Element Helium
Helium, the second most abundant element in the universe, was discovered on the sun before it was found on the earth.
Helium is commercially recovered from natural gas deposits, mostly from Texas, Oklahoma and Kansas.
Helium is combined with oxygen to create a nitrogen free atmosphere for deep sea divers so that they will not suffer from a condition known as nitrogen narcosis.
education.jlab.org /itselemental/ele002.html   (420 words)

  
 Periodic Table : Scholar edition: helium : The Essentials
Helium is one of the so-called noble gases.
Elemental helium is a colourless odourless monoatomic gas.
Helium is the second most abundant element in the universe after hydrogen.
www.webelements.com /webelements/scholar/elements/helium/key.html   (160 words)

  
 Liquid helium, superfluidity
When helium is cooled to a critical temperature of 2.17 K (called its lambda point), a remarkable discontinuity in heat capacity occurs, the liquid density drops, and a fraction of the liquid becomes a zero viscosity "superfluid".
An important application of liquid helium has been in the study of superconductivity and for the applications of superconducting magnets.
When helium is cooled to a critical temperature of 2.17 K, a remarkable discontinuity in heat capacity occurs, the liquid density drops, and a fraction of the liquid becomes a zero viscosity "superfluid".
hyperphysics.phy-astr.gsu.edu /hbase/lhel.html   (386 words)

  
 Helium Safety
During the exchange of gases in the normal breathing process, the blood stream absorbs oxygen from air in the lungs, while carbon dioxide passes from the blood to the air.
Helium balloon-filling systems have become popular in recent years, and are frequently found in supermarkets, party supply stores, and variety stores.
Attempting to inhale helium from a commercial helium balloon filling system poses a greater hazard than does inhaling helium from a balloon.
www.cganet.com /N2O/helium_safety.htm   (823 words)

  
 Chemistry : Periodic Table : helium : key information
There is very little helium on earth as nearly all present during and immediately after the earth's formation has long since been lost as it is so light.
While there is some helium in the atmosphere, currently its isolation from that source by liquefaction and separation of air is not normally economic.
Concentrations of helium in natural gas in the USA are as high as 7% and other good sources include natural gas from some sources in Poland.
www.webelements.com /webelements/elements/text/He/key.html   (318 words)

  
 Matador Records | Helium Biography
The long-awaited second album from Boston’s HELIUM is an unexpected departure from the fragmented, angry pop of yore.
Just a hint of the greatness of the full-length album to follow, Helium’s new material is less brutal, more gripping and everyone’s favorite at the Matador office.
Helium have been regrouping to add new bassist Ash from Polvo, and "Pat’s Trick" was recorded virtually entirely by Mary Timony alone (is this a trend?).
www.matadorrecords.com /helium/biography.html   (1163 words)

  
 helium
The only known helium extraction plants, outside the United States, in 1996 were in Eastem Europe (Poland), Russia, China, and India.
Using liquid helium, Kurti and co-workers, and others, have succeeded in obtaining temperatures of a few microkelvins by the adiabatic demagnetization of copper nuclei, starting from about 0.01 K. Seven isotopes of helium are known.
Liquid helium (He4) exists in two forms: He4I and He4II, with a sharp transition point at 2.174 K (3.83 cm Hg).
www.speclab.com /elements/helium.htm   (863 words)

  
 Helium
Except for hydrogen, helium is the most abundant element found through out the universe.
Helium has the lowest melting point of any element and is widely used in cryrogenic research because its boiling point is close to absolute zero.
Seven isotopes of helium are known: Liquid helium (He4) exists in two forms: He4I and He4II, with a sharp transition point at 2.174K.
www.corrosionsource.com /handbook/periodic/2.htm   (812 words)

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