Question

Calculate the effective nuclear charge of the last electron in an atom whose configuration is $1s^{2}2s^{2}2p^{6}3s^{2}3p^5$.

Answer 1

Z = 17
$Z^{\ast }=Z-S$
= 17 - [(0.35 $\times$ No. of other electrons in nth shell)] + (0.85 $\times$ No. of electrons in (n - 1)th shell) + (1.00 $\times$ total number of electrons in the inner shells)
$=17-\left[\right(0.35\times 6)+(0.85\times 8)+(1\times 2\left)\right]$
$=17-10.9=6.1$