Hello All, I'm a physics major and trying to figure out how "full" electronic shells are determined. It really reduces to the question why isn't Beryllium a noble gas? If an angular momentum subshells are what matters then the shells are: [tex] 1S^2 2S^2 [/tex]. Clearly the [tex]2S[/tex] subshell is full, yet this isn't considered a noble gas. Why?? Thanks a lot for any help.