This element is no longer available.
Helium is one of the noble gases of group O in the periodic table. It’s the second lightest element. The main helium source in the world is a series of fields of natural gas in the United States.
Helium is a colourless, odourless, insipid and non-toxic gas. It’s less soluble in water than any other gas. It’s the less reactive element and doesn’t essentially form chemical compounds. The density and viscosity of helium vapour are very low. The thermic conductivity and the caloric content are exceptionally high. Helium can be liquefied, but its condensation temperature is the lowest among all the known substances.
Helium has many unique properties: low boiling point, low density, low solubility, high thermal conductivity and inertness, so it is use for any application which can exploit these properties. Helium was the first gas used for filling balloons and dirigibles. This application goes on in altitude research and for meteorological balloons. The main use of helium is as an inert protection gas in autogenous welding. Its biggest potential is found in applications at very low temperatures. Helium is the only cooler which is capable of reaching temperatures lower than 15°K (-434°F). The main application of ultralow temperature is in the development of the superconductivity state, in which the resistance to the electricity flux is almost zero. Other applications are its use as pressurizing gas in liquid propellants for rockets, in helium-oxygen mixtures for divers, as working fluid in nuclear reactors cooled down by gas and as gas carrier in chemical analysis by gas chromatography.