Part one of term paper
, symbol He, inert, colorless, odorless gaseous element. In group 18 (or VIIIa) of the periodic table, is one of the noble gases. The atomic number of is 2. The French astronomer Pierre Janssen discovered in the spectrum of the corona of the sun during an eclipse in 1868. Helium is the lightest of all gases except hydrogen. Helium solidi ...

Part two of term paper
... with other elements extremely difficult and the resulting compounds quite unstable. Helium is the most difficult of all gases to liquefy and is impossible to solidify. These properties make liquid helium extremely useful as a refrigerant and for experimental work in producing and measuring temperatures close to absolute zero. Liquid helium can be cooled almost to absolute zero at normal pressure by rapid removal of the vapor above the liquid. At a temperature slightly above absolute zero, it is ...