Question

Electronic configurations of few elements are given below. Mark the incorrect match.

• A. $l{s}^{2}2s^{2}2p^5$ - Most electronegative element
• B. $l{s}^{2}2s^{2}2p^3$- An element belonging to 3rd period and 5th group
• C. $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}3d^{8}4s^2$ - A d-block element
• D. $1s^{2}2s^{2}2p^{6}3s^{2}3p^6$ - An element from 18th group

Answer 1

Answer: (B)

$l{s}^{2}2s^{2}2p^3$- An element belonging to 3rd period and 5th group

$l{s}^{2}2s^{2}2p^3$ is an element belonging to second period and 5th group (group VA or 15). From electronic configuration $l{s}^{2}2s^{2}2p^3$, we can say $n=2$ so that period is second and not third.