Look up: helium

1. 
   helium
   The second lightest and second most abundant element. The typical helium atom consists of a nucleus of two protons and two neutrons surrounded by two electrons. Helium was first discovered in our Sun. Roughly 25 percent of our Sun is helium.
   Found on http://antwrp.gsfc.nasa.gov/apod/lib/glo
   
   
2. 
   Helium
   Helium is a gaseous element with the symbol He.
   Found on http://www.encyclo.co.uk/nol.php
   
   
3. 
   helium
   [n] - a very light colorless element that is one of the six inert gasses
   Found on http://www.webdictionary.co.uk/definitio
   
   
4. 
   Helium
   Lighter than air gas, element He.
   Found on http://www.anson.co.uk/oilfield_glossary
   
   
5. 
   Helium
   At room temperature, helium is a colourless and odourless gas. After hydrogen, it is the chemical element with the lowest density and has the lowest melting point of all elements. As with all other noble gases (neon, argon, krypton, xenon) helium is very inert. Therefore there are no known helium compounds in nature. Helium (helium I) changes state at low temperatures (helium II). Helium II is the best conductor of heat known and has a heat conductivity which is 300 times higher than silver. In addition it flows without internal friction and penetrates even the tiniest of openings. Because of these properties, helium II is also referred to as a superfluid. In normal air, sound travels at a speed of around 330 metres per second, but in helium gas it travels at twice the speed. This explains the Mickey Mouse effect on the voice when helium is inhaled.
   Found on http://www.adixen.co.uk/glossary-vacuumt
   
   
6. 
   Helium
   An inert gaseous element. The atom is characterised by possessing two protons in its nucleus. Usually there two neutrons as well. This abundant form of helium is about four times as heavy as hydrogen. Helium accounts for just under one quarter of the atomic matter in the universe and was principally formed during the first few minutes after the big...
   Found on http://www.diracdelta.co.uk/science/sour
   
   
7. 
   Helium
   Discovered : by Sir William Ramsay in London, and independently by P.T. Cleve and N.A. Langlet in Uppsala, Sweden in 1895Origin : The name is derived from the Greek ‘helios`,sunDescription :A colourless, odourless gas that is totally unreactive. It is extracted from natural gas wells, some of which contain gas that is 7% helium. It is used in deep ...
   Found on http://www.allchemicals.info/index/actio
   
   
8. 
   helium
   He. Element 2, atomic weight 4.0026. A colorless, odorless, inert gas, first discovered in the emission spectrum of the sun in 1868.
   Found on http://antoine.frostburg.edu/chem/senese
   
   
9. 
   Helium
   An inert colourless gas, one-sevcnth of the weight of air. It is preferable to hydrogen for use in airships because it is non-inflammable. Unfortunately it is very costly and is only found in workable quantities in North America, and it is twice as heavy as hydrogen.
   Found on http://www.aeroplanemonthly.com/glossary
   
   
10. 
    helium
    it is used in high-pressure gas systems in rockets and for inflating balloons and airships. Category: Chemistry • chemical element:atomic number 2 Category: Chemistry
    Found on http://www.mijnwoordenboek.nl/definition
    
    
11. 
    Helium
    He'li·um noun [ New Latin , from Greek ... the sun.] (Chemistry) A gaseous element found in the atmospheres of the sun and earth and in some rare minerals.
    Found on http://www.encyclo.co.uk/webster/H/28
    
    
12. 
    Helium
    He'li·um (hē'lĭ*ŭm) noun [ New Latin , from Greek 'h`lios the sun.] (Chemistry) 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 Lockye ...
    Found on http://www.encyclo.co.uk/webster/H/28
    
    
13. 
    helium
    <element> A gas. Certain types of radiation therapy used charged, radioactive particles of helium. ... (16 Dec 1997) ...
    Found on http://www.mondofacto.com/facts/dictiona
    
    
14. 
    Helium
    `Helium` (`He`) is a colorless, odorless, tasteless, non-toxic, inert monatomic chemical element that heads the noble gas series in the periodic table and whose atomic number is 2. Its boiling and melting points are the lowest among the elements and it exists only as a gas except in extreme conditions. Extreme conditions are also needed to create the small handful of helium compounds, which are all unstable at standard temperature and pressure. I...
    Found on http://en.wikipedia.org/wiki/Helium
    
    
15. 
    helium
    (He) (he´le-әm) a chemical element, atomic number 2, atomic weight 4.003. It is a chemically inert element that is odorless, tasteless, and noncombustible.
    Found on http://www.mercksource.com/pp/us/cns/cns
    
    
16. 
    Helium
    • (n.) A gaseous element found in the atmospheres of the sun and earth and in some rare minerals. • (n.) 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 dete...
    Found on http://thinkexist.com/dictionary/meaning
    
    
17. 
    Helium
    (from the article `Keesom, Willem Hendrik`) ...joined the faculty of the Utrecht veterinary school. Six years later he returned to Leiden as professor of experimental physics. At the Onnes ...
    Found on http://www.britannica.com/eb/a-z/h/33
    
    
18. 
    helium
    chemical element, inert gas of Group 0 (noble gases) of the periodic table. The second lightest element (only hydrogen is lighter), helium is a ... [53 related articles]
    Found on http://www.britannica.com/eb/a-z/h/33
    
    
19. 
    helium
    A gaseous element present in minute amounts in the atmosphere (0.000524% of dry volume); atomic no. 2, atomic wt. 4.002602; used as a diluent of medicinal gases; used as a diluent of oxygen principally in nonmedical applications, and in its liquid form as the coolant for super-conducting magnets (as in magnetic resonance imaging). [G. hlios, the s...
    Found on
    
    
20. 
    helium
    (He) A prototype Venus balloon in a JPL cleanroom. Image credit: NASA/JPL-Caltech A colorless, odorless, unreactive gaseous element which is the second most abundant and second lightest element in the universe (after hydrogen). Helium is one of the inert gases (also k...
    Found on http://www.daviddarling.info/encyclopedi
    
    
21. 
    helium
    helium (hē'lēum) , gaseous chemical element; symbol He; at. no. 2; at. wt. 4.0026; m.p. below -272°C at 26 atmospheres pressure; b.p. -268.934°C at 1 atmosphere pressure; density 0.1785 grams per liter at STP; valence usually 0.Spectroscopic evidence for the presence of heliu...
    Found on http://www.infoplease.com/ce6/sci/A08232