Q. The number of $d$-electrons retained in $Fe^{2 +}$(At. No. Fe=26) ions is
A) 3
B) 4
C) 5
D) 6
Explanation
(d)
$\ _{26}Fe = \lbrack Ar\rbrack 3d^{6}4s^{2}$
$Fe^{2 +}$(24 electrons)=$\lbrack Ar\rbrack 3d^{6}4s^{0}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.