Question

The electron affinity values of elements $A, B, C$ and $D$ are respectively $-135,-60,-200$ and $-348\, kJ \,mol ^{-1}$ The outer electronic configuration of element $B$ is

• A. $3 s^{2} 3 p^{5}$
• B. $3 s^{2} 3 p^{4}$
• C. $3 s^{2} 3 p^{3}$
• D. $3 s^{2} 3 p^{2}$

Answer 1

Answer: (C)

Elements having half or completely-filled orbitals, ie, having stable electronic configuration have very low negative value of electron affinity. Since, the electron affinity of $B$ is lowest among the given, it has stable electronic configuration, ie, $3 s^{2}, 3 p^{3}$