2 He 4.0026022
Helium
NOBLE GAS
Phase: Gas
Discovered: Pierre Janssen
Block: S
Summary
Helium is 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 all the elements.
Source: WikipediaPhysical Properties
Atomic Mass 4.0026022 u
Density 0.1786 g/cm³
Melting Point 0.95 K
Boiling Point 4.222 K