Question

Which of the following have same number of electrons in outermost orbit?

• A. Pb, Sb
• B. N, O
• C. As, Bi
• D. P, Ca

Answer 1

The correct option is C As, Bi

As an Bi are in same group. So, they have same valence electron configuration.
$As=\left[Ar\right]3d^{10}4s^{2}4p^3$
$Bi=\left[Xe\right]4f^{14}5d^{10}6s^{2}6p^3$