Answer: The outer electrons
Step-by-step explanation:
Hydrogen has one electron shell; lithium has two; sodium has three..., and the outermost shell of those elements contains the valence electrons. Noble gases have eight, and alkaline and alkaline earth metals have 1 and 2 respectfully. The metals usually have 1, 2, or 3, and elements in groups 13 through 17 have 3 to 7 valence electrons per atom.