He

Helium

Definition From "helias" or sun. It is the second most abundant element in the universe, after hydrogen. Lighter than air, the most difficult of all gases to liquify and is impossible to solidify at atmospheric pressure.

Discovery 1868 by Pierre Janssen of France

Group of Elements Noble gas(Gas)

Atomic Weight 4.00260

Oxidation State 0

Melting Point -248.7

Boiling Point -268.9

Density 0.124 g/cm3