Multiple choice The electronic configuration of Sc+ (For Sc, atomic number is 21) is (Ar) 4s2 (Ar) 3d1 4s2 (Ar) 3d1 4s1 None of these - Reveal answer Fill a bubble to check yourself C Correct answer Explanation Sc+ means that one electron has been donated, i.e. its electronic configuration would be less than one electron from scandium.