Question

The $Z_{eff}$ (approx.) for $4s$-electron of $Ni$-atom according to Slater's rule is ________.

Answer 1

The configuration of Ni-atom is $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{2}3d^8$.

Hence the $Z_{eff}$ for 4s electron $=Z-S^{\ast }$

where, Z is the number of protons in the nucleus, and $S^{\ast }$ is the shielding constant.

$\therefore Z_{eff}=28-(0.35\times 1+0.85\times 16+1\times 10)$

$=28-23.95$

$=4.05$