Helium belongs to the noble gas family. These are Group 18 on the periodic table, or the outermost column on the right side. Another name for the noble gases is the inert gases, because they normally do not react with other elements.
In 1868, Pierre Janssen detected a yellow spectrum line while observing a solar eclipse. Norman Lockyer realized this was a new element, which he named helium. In 1895, William Ramsay discovered helium on earth by isolating it from a rare mineral called clevite.
Helium has the atomic number of 2 and has very low boiling and melting points. Its chemical symbol is He.
Other Group 18 elements are argon, neon, krypton, xenon and radon. Noble gases have a complete valence shell and high ionization energies. In 1875, Henry Cavendish discovered the noble gases when he isolated them by the chemical removal of nitrogen and oxygen from air.