Ionization energy, what's needed to remove 1 electron from 1 atom, is high for this non-reactive 6-element group
.... the first ionization energies (IE1) for some of the elements in the first 
group,... [DOC] [TLE] CHAPTER 6 PERIODIC TABLE [PAR] Nov 22, 2005 ... period 1  2 elements valence electrons in PEL 1; period 2  8 ...