This development tells us the deeper into your rows you go the greater shells you have. So when you had Bromine, one example is, it would have 4 shells. So the quantity of shells is depending on the row variety it is in. The first dissociation curves from Bohr's experiments http://umtsflatvergleich.de/die-vorteile-der-verwendung-einer-hebebuhne-in-ihrem-trainingsprogramm/