• WordNet 3.6
    • n helium 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)
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Webster's Revised Unabridged Dictionary
  • Interesting fact: By weight, the sun is 70% hydrogen, 28% helium, 1.5% carbon, nitrogen, and oxygen, and 0.5% all other elements.
    • n Helium hē"lĭ*ŭm (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.
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Century Dictionary and Cyclopedia
  • Interesting fact: The sun is approximately 75% hydrogen, 25% helium by mass
    • n helium A hypothetical elementary substance, known only by the lines ascribed to it in the solar spectrum.
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Chambers's Twentieth Century Dictionary
  • Interesting fact: The three most common elements in the universe are 1) hydrogen; 2) helium; 3) oxygen.
    • n Helium hē′li-um a substance discovered by Lockyer in the sun's atmosphere, found by Ramsay in the rare Norwegian mineral cleveite.
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Webster's Revised Unabridged Dictionary
NL., fr. Gr. "h`lios the sun


In literature:

Half helium and half oxygen.
"The Man Who Hated Mars" by Gordon Randall Garrett
Helium was actually at hand, and available for examination.
"A Popular History of Astronomy During the Nineteenth Century" by Agnes M. (Agnes Mary) Clerke
Its spectrum shows that it is composed chiefly of hydrogen, calcium and helium, in the state of vapour.
"Astronomy of To-day" by Cecil G. Dolmage
Possibly a few atoms of helium.
"Spawn of the Comet" by Harold Thompson Rich
The element helium was first isolated by Ramsey some twenty-seven years later.
"Astounding Stories of Super-Science April 1930" by Various
In the name of the people of Helium I demand fair and impartial treatment for the Prince of Helium.
"The Gods of Mars" by Edgar Rice Burroughs
The helium compound gradually breaks down, giving rise to the helium observed.
"A History of Science, Volume 5(of 5)" by Henry Smith Williams
No bends for either of us, because of the helium substitution for nitrogen.
"The Trouble with Telstar" by John Berryman
Some of them are more familiar than hydrogen and helium.
"Letters of a Radio-Engineer to His Son" by John Mills
It was too deep for me, but it is based upon changing hydrogen into helium, I think.
"Astounding Stories of Super-Science, December 1930" by Various

In news:

Helium shortage is raising prices for everyone from physicists and hospitals to retailers of Mylar balloons.
Shortage brings rise in price of helium .
The Weird Story Of Why Helium Prices Are Going Through The Roof.
Temporary helium shortage hits party-balloon business.
A helium shortage, however, has led to a huge drop in participation for their famous cross-country race.
Short on Helium , Long on News.
New helium balloon ride at WonderWorks.
The helium balloon ride is opening after a three month delay due to a national shortage of helium .
Western Digital's HGST: Helium -Filled Hard Drives.
Reba Bettwy's been in the party supply business since 2008, supplying helium -filled balloons for her customers.
Global helium shortage felt in Buffalo.
This time it's helium and as ever, the story is driven by people not really understanding what a resource actually is.
But lately, you should also think about helium prices — because they're soaring, too.
Gibbons on helium sing like sopranos.
Gibbons on helium sing like opera stars.

In science:

Together with the increased rate of helium production, this allows He ignition at a lower column depth, as seen in Figure 1(a).
Rotational Evolution During Type I X-Ray Bursts
This is because both the spin down and thermal time are less for the pure helium bursts (∆zc ∝ 1/µ and ttherm ∝ 1/µ).
Rotational Evolution During Type I X-Ray Bursts
Our results show that there are important differences in spin evolution depending on whether the helium ignites in a pure helium or mixed H/He environment.
Rotational Evolution During Type I X-Ray Bursts
The dashed lines are for pure helium ignitions, ˙m = 0.01 ˙mEdd , ZCNO = 0.01 (upper curve) and ˙m = 0.015 ˙mEdd , ZCNO = 0.01 (lower curve).
Rotational Evolution During Type I X-Ray Bursts
In the case of helium, however, the parameter n|a|3 is of the order of 1, so that the theory looses most of its predictive power.
Helium nanodroplets and trapped Bose-Einstein condensates as prototypes of finite quantum fluids