Helium s a chemical element with the symbol He and atomic number 2. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas, the first in the noble gas group in the periodic table. Its boiling and melting point are the lowest among all the elements. Helium is the second lightest and second most abundant element in the observable universe (hydrogen is the lightest and most abundant)

As with any gas whose density differs from that of air, inhaling a small volume of helium temporarily changes the timbre and quality of the human voice.

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