Question

can a electron in a orbital exchange position to a empty orbital?

Answer 1

Not entirely sure , by i think they may

Answer 2

Unless energy is being added (I think) then this will only happen if it's a lower energy state. (e.g. ground state).

Answer 3

Only certain transitions are allowed...

Answer 4

if a photon strikes atom, the valence electron can be excited enough to change its orbital position.

Answer 5

yes...it can even leave the atom...but it need to get energyy from somewhere