Answer:
It's funny cause i'm doing the same exact thing as you.
Explanation:
You need to go to the Gizmo, and it explains everything. But When you're looking at "Valence Electrons" thats how many "dots" (electrons) there are on the outermost circle, so Fluorine has 7 Valence Electrons. To find the valency, you need to first identify the Valence Electrons. Fluorine has 7 valence electrons, and it would be a lot easier for this atom to gain an electron, rather than lose 7. So 8-7 is 1, meaning the Valency of Fluorine will be 1. For the sum, just add the total number, so 7+1 is 8, so the sum of Fluorine will be 8. This is confusing, so I'm sorry if this doesn't make sense.
