Question

Number of electrons having $l+m$ value equal to zero in ${}_{26}Fe$ may be

Answer 1

Answer: 13

${}_{26}Fe-1s^2,2s^{2}2p^6,3s^{2}3p^6,3d^6,4s^2$
$l+m=0\Rightarrow l=0,m=0i.e.s$-subshell
$l=1,m=-1$ i.e. one orbital of $p$ .
$l=2,m=-2$ i.e. one of $d$ -orbitals
Hence there are $13$ or $14$ electrons as in $d$-orbital there may be one or two electrons having $m=-2$.