I understand that some atoms have somewhat stable states at states other than the ground state. What I don't understand is how are compounds able to be made with these metastable atoms? Wouldn't the energy released uppon forming the compound or the increased energy needed just immediately disrupt the metastable. If you had a metastable helium ion floating around it could never combine and form a diatomic helium molecule and still have its electrons in their metastable shells right? Edit: Well other than the fact that heluim isn't diatomic except at millikelvin temps.