Related Searches
on Ask.com
helium
- 11 dictionary resultshe⋅li⋅um
[hee-lee-uh
m] 
–noun
| an inert, gaseous element present in the sun's atmosphere and in natural gas, and also occurring as a radioactive decomposition product, used as a substitute for flammable gases in dirigible balloons. Symbol: He; atomic weight: 4.0026; atomic number: 2; density: 0.1785 g/l at 0°C and 760 mm pressure. |
lihelium I
–noun
| colorless liquid helium existing below its boiling point of 4.2 K and above the lambda point of 2.186 K. |
helium II
–noun
| liquid helium existing as a superfluid below the lambda point of 2.186 K, having very low viscosity and very high thermal conductivity. |
Dictionary.com Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2009.
Cite This Source
Based on the Random House Dictionary, © Random House, Inc. 2009.
Cite This Source
|
Link To helium
| he·li·um (hē'lē-əm) n. Symbol He A colorless, odorless inert gaseous element occurring in natural gas and with radioactive ores. It is used as a component of artificial atmospheres and laser media, as a refrigerant, as a lifting gas for balloons, and as a superfluid in cryogenic research. Atomic number 2; atomic weight 4.0026; boiling point -268.9°C; density at 0°C 0.1785 gram per liter. See Table at element. [From Greek hēlios, sun (so called because its existence was deduced from the solar spectrum); see sāwel- in Indo-European roots.] |
The American Heritage® Dictionary of the English Language, Fourth Edition
Copyright © 2009 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
Cite This Source
Copyright © 2009 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
Cite This Source
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.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.
Webster's Revised Unabridged Dictionary, © 1996, 1998 MICRA, Inc.
Cite This Source
Cite This Source
Language Translation for : helium
Spanish:
helio,
German:
das Helium,
Japanese:
ヘリウム
The American Heritage® New Dictionary of Cultural Literacy, Third Edition
Copyright © 2005 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
Cite This Source
Copyright © 2005 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
Cite This Source
helium
1868, coined from Gk. helios "sun" (see sol), because the element was observed in the solar spectrum during the eclipse of Aug. 18, 1868, by Eng. astronomer Sir Joseph N. Lockyer (1836-1920) and Eng. chemist Sir Edward Frankland (1825-99). It was not actually obtained until 1895.
Online Etymology Dictionary, © 2001 Douglas Harper
Cite This Source
Cite This Source
Main Entry: he·li·um
Pronunciation: 'hE-lE-&m
Function: noun
: a light colorless nonflammable gaseous element found especially in naturalgases and used chiefly for inflating airships and balloons, for filling incandescent lamps, and for cryogenic research —symbol He; —see
Merriam-Webster's Medical Dictionary, © 2002 Merriam-Webster, Inc.
Cite This Source
Cite This Source
helium he·li·um (hē'lē-əm)
n.
Symbol He
An inert gaseous element occurring in natural gas and used as a component of artificial atmospheres and laser media. Atomic number 2; atomic weight 4.0026; boiling point -268.9°C; density at 0°C 0.1785 gram per liter.
The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Cite This Source
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Cite This Source
| helium (hē'lē-əm) Pronunciation Key
Symbol He A very lightweight, colorless, odorless element in the noble gas group. Helium occurs in natural gas, in radioactive ores, and in small amounts in the atmosphere. It has the lowest boiling point of any substance and is the second most abundant element in the universe. Helium is used to provide lift for balloons and blimps and to create artificial air that will not react chemically. Atomic number 2; atomic weight 4.0026; boiling point -268.9°C; density at 0°C 0.1785 gram per liter. See Periodic Table. Our Living Language : The second most abundant element in the universe after hydrogen, Helium (symbol He) is a colorless, odorless, nonmetallic gas that is produced abundantly by the nuclear fusion in all stars and is found in smaller amounts on Earth. It was discovered by the British scientist—and founding editor of the journal Nature—Joseph Norman Lockyer in 1868, while he was studying a solar eclipse with a spectroscope, an instrument that breaks light up into a spectrum. If an element is heated up enough to glow, the emitted light produces a unique spectrum when refracted through a prism. Lockyer noticed that the spectrum of the Sun's corona, which is visible only during a solar eclipse, contained lines produced by an unknown element. He named the element helium from helios, the Greek word for "sun." Helios gives us many other words pertaining to the Sun, such as heliocentric and perihelion. |
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source
Copyright © 2009, Dictionary.com, LLC. All rights reserved.
