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Helium   Listen
noun
Helium  n.  (Chem.) An inert, monoatomic, gaseous element occurring in the atmosphere of the sun and stars, and in small quantities in the earth's atmosphere, in several minerals and in certain mineral waters. It is obtained from natural gas in industrial quantities. Symbol, He; atomic number 2; at. wt., 4.0026 (C=12.011). Helium was first detected spectroscopically in the sun by Lockyer in 1868; it was first prepared by Ramsay in 1895. Helium has a density of 1.98 compared with hydrogen, and is more difficult to liquefy than the latter. Chemically, it is an inert noble gas, belonging to the argon group, and cannot be made to form compounds. The helium nucleus is the charged particle which constitutes alpha rays, and helium is therefore formed as a decomposition product of certain radioactive substances such as radium. The normal helium nucleus has two protons and two neutrons, but an isotope with only one neutron is also observed in atmospheric helium at an abundance of 0.013 %. Liquid helium has a boiling point of -268.9° C at atmospheric pressure, and is used for maintaining very low temperatures, both in laboratory experimentation and in commercial applications to maintain superconductivity in low-temperature superconducting devices. Gaseous helium at normal temperatures is used for buoyancy in blimps, dirigibles, and high-altitude balloons, and also for amusement in party balloons.






Collaborative International Dictionary of English 0.48








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"Helium" Quotes from Famous Books



... $ 130 billion in spending by shrinking departments, extending our freeze on domestic spending, cutting 60 public housing programs down to 3, getting rid of over a hundred programs we do not need like the Interstate Commerce Commission and the Helium ...
— Complete State of the Union Addresses from 1790 to the Present • Various

... it at six pounds in the ships. Half helium and half oxygen. Only thing that bothers me is the oxy here. Or rather, the oxy that isn't here." He took a deep breath through his nose tube to emphasize ...
— The Man Who Hated Mars • Gordon Randall Garrett

... Scientist, "helium shares in the most intimate degree the properties of radium. So, too, for the matter of that," he added in afterthought, "do ...
— Frenzied Fiction • Stephen Leacock

... business girl observed judiciously. "The way sales have been plummeting, it won't be long before the Government deeds our desks to the managers of Fairy Bread and asks us to take the Big Jump. But just where does your quick thinking come into this, Mr. Snedden? You can't be referring to the helium—that was ...
— Bread Overhead • Fritz Reuter Leiber

... may exist undiscovered in the dust we tread or in the air we breathe. In the year 1895 two new terrestrial elements were discovered; but one of these had for years been known to the astronomer as a solar and suspected as a stellar element, and named helium because of its abundance in the sun. The spectroscope had reached out millions of miles into space and brought back this new element, and it took the chemist a score of years to discover that he had all along had samples of the same substance unrecognized ...
— A History of Science, Volume 3(of 5) • Henry Smith Williams

... about 180,000 miles per second. The [gamma]-rays are probably pulsations of the ether, the medium supposed to fill space. The emission of [alpha]-rays by radium is accompanied by the production of the inert elementary gas, helium; therefore, the [alpha]-rays are, or quickly change into, rapidly moving particles of helium. The particles which constitute the [beta]-rays carry electric charges; these electrified particles, each approximately a thousand ...
— The Story of Alchemy and the Beginnings of Chemistry • M. M. Pattison Muir

... there with pentothal in your veins and wires running out of your head and tell them about the still waters of Korus, or the pennons flying from the twin towers of Greater Helium or the way the tiny, slanting sun gleamed at dawn through the ...
— The Hills of Home • Alfred Coppel



Words linked to "Helium" :   argonon, atomic number 2, he, element, chemical element, helium group



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