Recent content by newforce

Thanks so much for the excellent reference! I will read it carefully.

Thanks for your reply. Your idea currently is only reasonable explanation for the missing transition though I still expect more details. BTW, graph in the link clearly shows no transition between 1s3p-1s3s.

For S=0 parahelium, 1s2p-1s2s transition is allowed, but why there is no transition between 1s3p-1s3s? I think the only difference for the electron configurations is principal quantum number. The selection rules applying for 1s2p-1s2s can also be applied to 1s3p-1s3s. In other words, there is...