How is an elements outer electron configuration related to its position in the periodic table?

Well, if you look at group 1 of the periodic table, you will notice a thrend. All elements in group 1 have 1 valence / outer electron. Then you look at period 2, 3, 4 and so on, you will see that the group number corresponds the number of valence/ outershell electrons. Hence, the group determines the electron(s) on the outershell.

Both models are effective because they show the valence electrons, and these valence electrons indicate the reactivity of an element.