Q. The electronic configuration of the element with maximum electron affinity is
A) $1s^{2},2s^{2},2p^{3}$
B) $1s^{2},2s^{2},2p^{5}$
C) $1s^{2},2s^{2},2p^{6},3s^{2},3p^{5}$
D) $1s^{2},2s^{2},2p^{6},3s^{2},3p^{3}$
Explanation
(c)
Generally electron affinity increases in a period and decreases in a group but due to smaller size and high electron density on fluorine atom, it experience high interelectronic repulsions. Thus, $F^{-}$ion is less stable in comparison to $Cl^{-}$ion. Hence, electron affinity is highest for chlorine. Its electronic configuration is
$\ _{17}Cl = 1s^{2},2s^{2}2p^{6},3p^{2},3p^{5}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.