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more about helium
helium |
4 definitions found From Webster's Revised Unabridged Dictionary (1913) [web1913]: Helium \He"li*um\ (h[=e]"l[i^]*[u^]m), n. [NL., fr Gr "h`lios the sun.] (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. Symbol, He at wt., 4. 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 belongs to the argon group and cannot be made to form compounds. It is a decomposition product of the radium emanation. From Webster's Revised Unabridged Dictionary (1913) [web1913]: Helium \He"li*um\, n. [NL., fr Gr ? the sun.] (Chem.) A gaseous element found in the atmospheres of the sun and earth and in some rare minerals. From WordNet r 1.6 [wn]: helium n : a very light colorless element that is one of the six inert gasses; the most difficult gas to liquefy; occurs in economically extractable amounts in certain natural gases (as those found in Texas and Kansas) [syn: {He}, {atomic number 2}] From Elements database 20001107 [elements]: helium Symbol: He Atomic number: 2 Atomic weight: 4.0026 Colourless, odourless gaseous nonmetallic element. Belongs to group 18 of the periodic table. Lowest boiling point of all elements and can only be solidified under pressure. Chemically inert, no known compounds. Discovered in the solar spectrum in 1868 by Lockyer.
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