how is there evidence for shells in atom and in periods.
I looked at all my resources and online I still have no clue!!! Does an atom need to have single filled sub shells for it to have low ionisation energy... I have no idea!!
Also, what electron configuration must an atom have in order for it to have a low ionisation energy, i'm talking about the way oxygen and nitrogen have different IE but similar electron configurations
Plz help ;(
What should I do?