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Helium is found in large amounts in minerals of uranium and thorium, including uraninite and its varieties cleveite and pitchblende, [20] [137] carnotite and monazite (a group name; "monazite" usually refers to monazite-(Ce)), [138] [139] because they emit alpha particles (helium nuclei, He 2+) to which electrons immediately combine as soon as ...
The Crude Helium Enrichment Unit in the Cliffside Gas Field. Remnants of the Amarillo Helium Plant in 2015. The National Helium Reserve, also known as the Federal Helium Reserve, is a strategic reserve of the United States, which once held over 1 billion cubic meters (about 170,000,000 kg) [a] of helium gas.
Terrestrial helium consists almost exclusively (all but ~2ppm) [16] of 4 He. 4 He's boiling point of 4.2 K is the lowest of all known substances except 3 He. When cooled further to 2.17 K, it becomes a unique superfluid with zero viscosity. It solidifies only at pressures above 25 atmospheres, where it melts at 0.95 K.
An observation of the new yellow line had been made earlier by Janssen at the 18 August 1868 solar eclipse [13], and because their papers reached the French academy on the same day, he and Lockyer usually are awarded joint credit for helium's discovery. Terrestrial helium was found about 27 years later by the Scottish chemist William Ramsay.
Helium usually makes up a minuscule portion of natural gas, but can make up as much as 10 percent of natural gas in some fields. A helium content of 0.3 percent or more is considered necessary for commercial helium extraction. [1] In 2012, helium was recovered at 16 extraction plants, from gas wells in Colorado, Kansas, Oklahoma, Texas, and ...
Materials on the Moon's surface contain helium-3 at concentrations estimated between 1.4 and 15 parts per billion (ppb) in sunlit areas, [1] [63] [64] and may contain concentrations as much as 50 ppb in permanently shadowed regions. [65] For comparison, helium-3 in the Earth's atmosphere occurs at 7.2 parts per trillion (ppt).
[18] [19] Samples of the lithium ore spodumene from Edison Mine, South Dakota were found to contain 12 parts of helium-3 to a million parts of helium-4. Samples from other mines showed 2 parts per million. [18] Helium is also present as up to 7% of some natural gas sources, [20] and large sources have over 0.5% (above 0.2% makes it viable to ...
Pages in category "Isotopes of helium" The following 10 pages are in this category, out of 10 total. This list may not reflect recent changes. ...