As is in group 5A and all elements in that group have 5 valence electrons. If you go over one group to group 6A, all those elements (O,S,Se,Te,Po) will have 6 valence electrons.However, the elements in the middle (the transition elements) will act a little differently...s (Arsenic) has five valence electrons Here's the electron configuration: [Ar]4sÂ²3dÂ¹â°4pÂ³ You can also just look at the group numbers (the column numbers for the old numbering system) and it will tell you how many valence electrons there are, instead of looking at the electron configuration.