My text material says:
$\mathrm{Z_{eff}= Z-S}$ where $\mathrm{Z_{eff}}$ is the effective nuclear change on that specified electron; $\mathrm{Z}$ is the atomic number and $\mathrm{S}$ is the shielding constant or screening constant which is the measure of net repulsion on that electron caused by other electrons in the same shell and inner shells.
So I infer that the Effective Nuclear Force on the electron of our interest (supposing it lies in the outermost orbit) is the resultant of the Force of the Nucleus minus the repulsion of the other electrons. Am I correct in assuming that? Can "charge" and "force" be analogous in here? If so, by Coulomb's law, shouldn't the closer orbitals repulse the electron more than the ones that are further away? Or in other words, shouldn't the Shielding constant be getting higher as we approach the outermost orbit?
But the values in Slater's rule shows the opposite:
the shielding experienced by an $\mathrm{s-}$ or $\mathrm{p-}$ electron, electrons within same group shield $\mathrm{0.35}$, except the $\mathrm{1s}$ which shield $\mathrm{0.30}$ electrons within the $\mathrm{n-1}$ group shield $\mathrm{0.85}$ electrons within the $\mathrm{n-2}$ or lower groups shield $\mathrm{1.00}$ the shielding experienced by $\mathrm{nd}$ or $\mathrm{nf}$ valence electrons electrons within same group shield $\mathrm{0.35}$ electrons within the lower groups shield $\mathrm{1.00}$
Implying that the further we move from the outermost electron, the Shielding or the Repulsion increases, which sounds the opposite of Coulomb's law to me.
What am I missing here?
Source:
- Chemistry LibreText - Slater's rules
- Concise Inorganic Chemistry by J.D. Lee