Question

The outer electronic configuration $s^2{p}^5$ is possessed by

• A. Ar
• B. Cu
• C. Cl
• D. Na

Answer 1

Answer: (C)

${}_{18}Ar:1s^2,2s^2,2p^6,3s^2,3p^6$
${}_{29}Cu:1s^2,2s^2,2p^6,3s^2,3p^6,3d^{10},4s^1$
${}_{17}Cl:1s^2,2s^2,2p^6,3s^2,3p^5$
${}_{11}Na:1s^2,2s^2,2p^6,3s^1$