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helium [He]

From the Greek helios meaning sun Discovered 1872 [1] Discovered on earth in 1895 by William Ramsay. [2] Discovered in the sun's spectrum in 1868 by Janssen & Lockyear. Occurrence: 1) natural gas deposits within the earth 2) can be isolated from air (lowest of any element) Characteristics: 1) light colorless non-flammable gaseous element 2) boiling point 4.2 degrees Kelvin Uses: 1) inflating airships & balloons 2) filling incandescent lamps 3) deep sea diving, added to air to protect againts the bends 3) cryogenic research

Related

periodic table

General

inert gas (noble gas, rare gas) bioagent

Properties

SIZE: AW = 4.0026 atomic number VALUE: 2 VALENCE: 1S2

References

  1. Webster's Ninth New Collegiate Dictionary, Miriam- Webster Inc. Springfield, MA 1990
  2. Chemical & Engineering News, Sept 8, 2003

Component-of

heliox (helium/oxygen) helium/n2/o2 helium/o2 helium/oxygen