Well first you can not go to the 2nd energy level without the first so the first takes up 2 electrons leaving you 5 electrons and the recommended amount is 8 electrons so you would have 5 electrons left
Draw a schematic and determine your thermal resistance values.
I think the answer is 3, population.
(20 seconds / 40 vibes) = (20/40) (seconds/vibe) = 0.5 second