Home 2 He Helium back to the periodic table
 
Atomic number   2
Symbol   He
Atomic weight   4.002602
Density [g/l]   0.17
Melting point [°C]   -271.0
Boiling point [°C]   -268.9
1st Ionization energy [eV]   24.587
Electronic configuration   1s2
Oxidation number (most stable)   ---
Atomic radius [pm]   128
Ionic radius [pm]   ---
Abundance in crustal rocks [ppm]   ---
Origin of the name   (greek) helios = sun, because of its occurence in the sun
Discovery   1895 by the English scientist  W. Ramsay
Uses   as a filler of fluorescent tubes, for filling of bolloons and in liquid form as a cooling medium.
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 © 2004 Büro für angewandte Mineralogie · Dr. Stephan Rudolph · D-47918 Tönisvorst
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