Daily Archives: May 18, 2015



Helium Atom 1
Basic Helium Facts Name: Helium Atomic Number: 2 Element Symbol: He Group: 18 Period: 1 Block: s Element Family: Noble Gas Atomic Mass: 4.002602(2) Electron Configuration: 1s2 Discovery: First identified: Pierre Janssen in 1868. First Isolated: Sir William Ramsay in 1895. Janssen was a French astronomer who observed a new yellow spectral line while observing a […]

Helium Facts – Atomic Number 2 or He