Helium (He)

Helium (He)

Atomic Number: 2
Atomic Weight: 4.00
Melting Point: -272.2
Boiling Point: -268.93
Specific Gravity: n/a
Valence(s): 0

The existence of Helium was first noted by Janssen in 1868, but it was not discovered until 1895. Helium is the 2nd-most abundant element (behind Hydrogen) in the Universe. The energy of the Sun and Stars is based on Helium reactions. Helium is used to lift gas balloons, to cool in nuclear reactors and to freeze in cryogenics. [LM] {RW}