Question

Number of electrons having $\ell +m$ value equalto zero in ${}_{26}Fe$ may be

• A. 13
• B. 15
• C. 7
• D. 12

Answer 1

The correct option is A 13

E.C. of Fe $=1s^2,2s^2,2p^6,3s^2,3p^6,3d^6,4s^2$

$l+m=0$

$l=0,m=0,$ i.e. s-subshell. So, total electrons in $s=$ 2+2+2+2=8.

$l=1,m=-1,$ i.e. one orbit of p. So total electrons in p having this condition=2+2=4.

$l=2,m=-2,$ i.e. one of d-orbitals. So, there can be 1 or 2 electrons in $m=2$ for d-subshell since there are total 6 electrons in 3d subshell.

Hence, there are 13 or 14 electron as in d-orbital it may be one or two electrons having $m=2$