Lexic.us

Definition of Helium

1. Noun. 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).

Definition of Helium

1. n. A gaseous element found in the atmospheres of the sun and earth and in some rare minerals.

2. 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 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.

Definition of Helium

1. Noun. A colorless and inert gas, and the second lightest chemical element (''symbol'' He) with an atomic number of 2 and atomic weight of 4.002602. ¹

2. Noun. A form or sample of the element. ¹

¹ Source: wiktionary.com

Definition of Helium

1. a gaseous element [n -S]

Medical Definition of Helium

1. A gas. Certain types of radiation therapy used charged, radioactive particles of helium. (16 Dec 1997)

Lexicographical Neighbors of Helium

Literary usage of Helium

Below you will find example usage of this term as found in modern and/or classical literature:

1. The Encyclopedia Americana: A Library of Universal Knowledge (1919)
"helium, the lightest of the group of so- called "inert gases" discovered in the ... The first terrestrial discovery of helium was made by Hillebrand (1889, ..."

2. Proceedings of the Royal Society of London by Royal Society (Great Britain) (1897)
"Had helium been removed, contraction would have occurred. ... Any compound of helium capable of existence will probably be endothermic, and the two methods ..."

3. The Encyclopaedia Britannica: A Dictionary of Arts, Sciences, Literature and (1910)
"helium is relatively abundant in many minerals, all of which are ... helium is contained almost universally in the gases which bubble up with the ..."

4. Aircraft Year Book by Manufacturers Aircraft Association (1921)
"Experimental work on helium production was started by the Bureau of Mines ... At that time not more than 100 cubic feet of helium had been isolated in the ..."

5. The Astrophysical Journal by American Astronomical Society, University of Chicago (1898)
"It is also known that helium which reaches the atmosphere uncom- bined must remain ... helium, which is probably uncombined, has now been detected as a ..."

6. Radioactive substances and their radiations by Ernest Rutherford (1913)
"PRODUCTION OF helium AND EMISSION OF HEAT. 227. Discovery of helium. In this chapter we shall discuss two important properties of active matter which have ..."

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