The allegory not only draws on the theory of forms, but it is connected both to the concept of forms and Plato's theory of the stages of life. 1  At the lowest stage, the cognitive stage of imagination (in Greek, eikasia), the prisoners exist bound and hindered in their perspective.
Since any orbital can hold a maximum of two electrons, the bonding orbital in H 2 + is only half-full. This single electron is nevertheless enough to lower the potential energy of one mole of hydrogen nuclei pairs by 270 kJ quite enough to make them stick together and behave like a distinct molecular species.
Shell 2 (2S & 2P) and Shell 3 (3S & 3P) each hold 8 electrons. After that, the next 2 hold 18 each, then the next 2 hold 32. So far, scientists havent discovered any elements that use more orbitals than this. As for how many shells the atom has, I already said that it has an infinite number of empty ones. But the number of full ones is probably closer to what youre looking for. For example, lets look at Calcium. Calcium has 20 electrons.