Who have you helped today--Sliders

Sliders
There are 5 elements that have exact symmetry in their electron distribution.
12 Magnesium 2 8 2
20 Calcium 2 8 8 2
38 Strontium 2 8 18 8 2
56 Barium 2 8 18 18 8 2
88 Radium 2 8 18 32 18 8 2
Four of these elements, all but magnesium, are called Sliders by Helen and have great power to give two of their electrons to make the following 8 elements have the power to give or share two electrons. They act much like parents giving for the next 8 children. The outside 2 electrons each of these elements end with, help each of the transitional elements be able to have electrons that they can give or share.