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.
Past hydrogen and helium, it's easiest to apply the octet rule to predict whether two atoms will form bonds and how many bonds they will form. Most atoms need 8 electrons to complete their outer shell. So, an atom that has 2 outer electrons will often form a chemical bond with an atom that lacks two electrons to be complete.