Atomic number: 2
Year discovered: 1868
Discovered by: Piere-Jules-César Janssen (1824-1907), French astronomer; and Sir Joseph Norman Lockyer (1836-1920), English astrophysicist.
- A French astronomer, Pierre-Jules-César Janssen, first obtained evidence for the existence of helium during the solar eclipse of 1868 in India when he detected new lines in the solar spectrum.
- No known element at that time was known to give these lines and so it was apparent that the sun contained an element not previously known.
- This initiated a search for the new element on planet earth.
- In 1895, Sir William Ramsay discovered helium in clevite, a uranium mineral.
- Sir William Crookes and Sir Norman Lockyer succeeded in identifying helium.
- It was discovered independently in clevite by Cleve and Langley at about the same time.
- Lockyer and Frankland suggested the name “helium”.
- There was a problem of proper apportionment of credit for the discovery of the gaseous nature of the helium.
- Janssen actually observed the bright lines in the spectrum of the chromosphere two months before Lockyer, but Lockyer conceived the idea of investigating the chromosphere with the spectroscope in 1866 and actually originated the method for doing it.
- Probably the first terrestrial helium was observed in a laboratory by W. F. Hillebrand, of the U. S. geological survey, in 1891, when he experimented with an inert gas which he obtained by heating uraninite, a uranium oxide.
- Hillebrand did not recognize the gas as a new element, in fact he rejected such a notion when it was suggested by one of his colleagues.
- It remained for Sir William Ramsay, a London professor, to discover the existence of helium on earth.
- Ramsay’s discovery of helium as a constituent of the earth was announced in simultaneous communications to the British Royal society and the French Academy of Sciences on March 26, 1895.
- In 1905, H. P. Cady and D. F. McFarland found that natural gas produced from a shallow well near Dexter, Kansas, contained 1.84% helium, and when helium bearing natural gas was found in other fields, large sources of helium became available.
- Helium gas is unreactive, colorless, and odorless.
- It is available in pressurized tanks and is the second most abundant element in the universe after hydrogen.
- Helium is used in lighter-than-air balloons and while heavier than hydrogen, is far safer since helium does not burn.
- Speaking after breathing an atmosphere rich in helium results in a squeaky, high pitched voice.
- There is very little helium on earth since nearly all that was present during and immediately after the earth’s formation has long since been lost as it is so light.
- While there is currently some helium in the atmosphere, its isolation from that source by liquefaction and separation of air is normally not economic.
- This is because it is easier, and cheaper, to isolate the gas from certain natural gases.
- Concentrations of helium in natural gas in the USA are as high as 7% and other good sources include natural gas from some sources in Poland.
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Information about other elements may be seen at this Chemical Elements List.
A special unit about words that include chemo-, chem- may be seen here.