Question

Covalent radius of ${}_{82}Pb$ is $1.53\mathring{A}$. Calculate its electronegativity (nearest integer value) at Allred-Rochow scale.

Answer 1

Allred-Rochow electronegativity is goven by:${\chi }^{AR}=\left(\frac{3590\times Z_{eff}}{r_{cov}^2}\right)+0.744$

$Z_{eff}=Z-S$

Electronic configuration of Pb is $\left[Xe\right]{4f}^{14}{5d}^{10}{4s}^2{6p}^2$

$S=0.35+0.85\left(18\right)+60=75.65$

Atomic number (Z) is 82.

$Z_{eff}=82-\left(75.65\right)Z_{eff}=6.35{\chi }^{AR}=\left(\frac{3590\times 6.35}{{(1.53\times {10}^{-2})}^2}\right)+0.744{\chi }^{AR}=1.71$

It is nearest to integer 2.