helium

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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 Periodic Table.

[From Greek hēlios, sun (so called because its existence was deduced from the solar spectrum); see sāwel- in Indo-European roots.]
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

helium

(ˈhiːlɪəm)
n
(Elements & Compounds) a very light nonflammable colourless odourless element that is an inert gas, occurring in certain natural gases: used in balloons and in cryogenic research. Symbol: He; atomic no: 2; atomic wt: 4.002602; density: 0.1785 kg/m3; at normal pressures it is liquid down to absolute zero; melting pt: below –272.2°C; boiling pt: –268.90°C. See also alpha particle
[C19: New Latin, from helio- + -ium; named from its having first been detected in the solar spectrum]
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014

he•li•um

(ˈhi li əm)

n.
an inert, gaseous element present in the sun's atmosphere and in natural gas, used as a substitute for flammable gases in dirigibles. Symbol: He; at. wt.: 4.0026; at. no.: 2; density: 0.1785 g/l at 0°C and 760 mm pressure.
[1872; < Greek hḗli(os) the sun + -ium2]
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.

he·li·um

(hē′lē-əm)
Symbol He A very lightweight, colorless, odorless element that is a noble gas and 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 chemically react. Atomic number 2. See Periodic Table.
Word History A lot of elements are named after the place they were first discovered—even if that place is 93 million miles away, as is the case with the element helium. In 1868 astronomers were studying a solar eclipse with a spectroscope, an instrument that breaks up light into a spectrum. When an element is heated hot enough to glow, the light emitted will produce a unique spectrum (pattern of lines) when refracted through a prism. The astronomers noticed that the spectrum of the sun's corona, which is only visible during an eclipse, contained some lines produced by an unknown element. The element was then named helium, from helios, the Greek word for "sun." We now know that helium is produced abundantly by the nuclear fusion in all stars, and is also found in smaller amounts on Earth. The Greek word helios gives us many other words pertaining to the sun, such as heliocentric and perihelion.
The American Heritage® Student Science Dictionary, Second Edition. Copyright © 2014 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.helium - a very light colorless element that is one of the six inert gasseshelium - 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)
chemical element, element - any of the more than 100 known substances (of which 92 occur naturally) that cannot be separated into simpler substances and that singly or in combination constitute all matter
argonon, inert gas, noble gas - any of the chemically inert gaseous elements of the helium group in the periodic table
Based on WordNet 3.0, Farlex clipart collection. © 2003-2012 Princeton University, Farlex Inc.
Translations
helium
هيليوم
хелий
heli
heliumhélium
helium
heliohelioaheliumo
heelium
هلیم
helium
הליום
हीलियम
helij
hélium
helium
helíumhelín
ヘリウム
헬륨
helium
helis
hēlijs
ഹീലിയം
hélio
heliu
hélium
helij
helijumхелијум
helium
heli
ฮีเลียม
helyum
гелій
helihêli

helium

[ˈhiːlɪəm] Nhelio m
Collins Spanish Dictionary - Complete and Unabridged 8th Edition 2005 © William Collins Sons & Co. Ltd. 1971, 1988 © HarperCollins Publishers 1992, 1993, 1996, 1997, 2000, 2003, 2005

helium

[ˈhiːliəm] nhélium m helium balloonhelium balloon nballon m gonflé à l'hélium
Collins English/French Electronic Resource. © HarperCollins Publishers 2005

helium

nHelium nt
Collins German Dictionary – Complete and Unabridged 7th Edition 2005. © William Collins Sons & Co. Ltd. 1980 © HarperCollins Publishers 1991, 1997, 1999, 2004, 2005, 2007

helium

[ˈhiːlɪəm] nelio
Collins Italian Dictionary 1st Edition © HarperCollins Publishers 1995

helium

(ˈhiːliəm) noun
an element, a very light gas which does not burn and which is used eg in balloons.
Kernerman English Multilingual Dictionary © 2006-2013 K Dictionaries Ltd.

he·li·um

n. helio, elemento gaseoso inerte empleado en tratamientos respiratorios y en cámaras de descompresión para facilitar el aumento o disminución de la presión del aire.
English-Spanish Medical Dictionary © Farlex 2012

helium

n helio
English-Spanish/Spanish-English Medical Dictionary Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved.
References in periodicals archive ?
"Eddie the Electron Moves Out" is a sequel to the exciting atomic science information book, "Eddie the Electron." Eddie is a rare helium atom who has popped out of a balloon and shot out into the world as a personified (cartoon) Helium atom.
Alternatively, when He[H.sup.+] reacts with CHS, it could lead initially to the same condensation adduct, CHS-H-[He.sup.+]*, but this time, exothermic expulsion of an excited helium atom could follow (see Fig.
The average velocity of He is obtained by [MATHEMATICAL EXPRESSION NOT REPRODUCIBLE IN ASCII] where [V.sub.i] is the velocity of the ith helium atom, <> means a time average, and NH is the total number of He atoms.
The first layer, which is made of a thin plastic, detects alpha particles, which are composed of two protons and two neutrons much like the nucleus of a helium atom. The second layer is made of gadolinium orthosilicate doped with cerium; this layer detects beta particles, which are highly charged electrons.
One oxygen atom weighs16 hydrogens, a carbon atom 12, a helium atom four and so on.
The reactor will try to reproduce the reactions that occur in the sun, in which two hydrogen atoms are forced together to produce one helium atom and a tiny amount of energy.
The other projects cover various areas, such as detecting diseases from the human breath, helium atom microscopy, the impact of perfluorinated hydrocarbons (PFCs), presumably resulting from industrial activity, on human health and obesity.
These streams of particles, called solar winds, are usually a low-density mixture of electrons, protons and helium atom cores, but there are periods of higher activity when the storms are more violent and the flow of particles is denser.
Thus, for example, an acceptable configuration for the two-electron [0.sup.+] ground state of the helium atom must take the form [MATHEMATICAL EXPRESSION NOT REPRODUCIBLE IN ASCII], where [j.sub.1] = [j.sub.2] and [[pi].sub.1] = [[pi].sub.2].
The Big Bang's nuclear reactions had produced only one helium atom for every 10 of hydrogen.
Photoinonization - or the photoelectric effect, which was discovered by Albert Einstein - in which an electron was seen exiting a helium atom after excitation by light.
This ratio turned out to be equal to that in a helium atom from which two electrons had been removed.