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.
A quick way to determine the number of valence electrons for a representative element is to look at which group is it in. Elements in group Ia have 1 valence electron. Elements in group IIa have 2 valence electrons. Can you guess how many valence electrons elements in group VIa have? If you guessed 6 valence electrons, then you are correct! The only group of representative elements that this method doesn't work for is group 0. Those elements certainly have more than 0 valence electrons; in fact, all of them except for helium have 8 valence electrons. Why doesn't helium have 8 valence electrons? Think for a moment about how many electrons helium has - it ...