a chemical element with symbol He and atomic number 2. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas that heads the noble gas group in the periodic table. Its boiling and melting points are the lowest among the elements and it exists only as a gas except in extreme conditions.

Ordinarily a colorless, inert gas, helium glows pale peach when an electric current runs through it. A glass blower bent a tube to the shape of the letters He and filled it with pure helium. I lit it with high voltage.