Gaseous element, first observed spectroscopically
in the sun during a solar eclipse in 1868. Its noncombustibility
and buoyancy make this extremely unreactive inert
Gas the most suitable of gases for balloons and airships.
Deep-sea divers often breathe a helium-and-oxygen
mixture because helium is less soluble in human blood
than nitrogen, its use reduces the risk of the bends.
Liquid helium is essential for low temperature work
Cryogenics, Superconductivity. Helium is also used
in arc welding and gas-discharge lasers.
in outer space, helium is the end product of fusion
processes in stars.