Helium

Position of helium in the periodic table.

Gas discharge tube filled with helium.

Helium is a chemical element with the symbol He and atomic number 2. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas and the first in the noble gas group in the periodic table. Its boiling and melting point are the lowest among all the elements. It is the second lightest and second most abundant element in the observable universe (hydrogen is the lightest and most abundant).

Uses

Helium's industrial uses include as a pressurizing and purge gas, as a protective atmosphere for arc welding, for cryogenic cooling, and in processes such as growing crystals to make silicon wafers, as well as a lifting gas in balloons and airships. He⁴, having an even number of particles, has a total spin of a whole number, meaning that it can form a Bose-Einstein condensate, useful for studying quantum mechanics. He³ can also do this, but needs to be cooled down more for the required Cooper pairs, since its spin is not a whole number.

Dependencies

• Helium
  • Silicon

See also

• Carbon
• Chlorine
• Hydrogen
• Iodine
• Nitrogen
• Oxygen
• Phosphorus
• Sulfur
• Chemical elements

References

This article uses material from the Wikipedia article Helium, which is released under the Creative Commons Attribution-ShareAlike 3.0 Unported License (view authors).