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.
Since the first orbital shell has only two electrons, we know that Boron has two shells: one with two 1s electrons and one with three electrons from the 2s and 2p orbitals. As another example, an element like chlorine will have three orbital shells: one with two 1s electrons, one with two 2s electrons and six 2p electrons, and one with two 3s electrons and five 3p electrons.