Question

Covalent radius of oxygen is 0.74 Å and its electronegativity is 3.5 . find effective nuclear charge experienced by oxygen?
Allred- Rochow electronegativityis given by $\chi =\frac{0.359Z_{eff}}{r^2}+0.744$
where $\chi$ is electronegativity, $r$= atomic radius, $Z_{eff}$ is effective nuclear charge

• A. 5.2
• B. 4.2
• C. 0.65
• D. 3.8

Answer 1

The correct option is B 4.2

Given, $\chi =3.5,r=0.74\AA$
the Allred- Rochow electronegativity formula is $\chi =\frac{0.359Z_{eff}}{r^2}+0.744$
where $Z_{eff}$ is effective nuclear charge and r is atomic radius.
substitue the values in above expression we get,
$3.5=\frac{0.359Z_{eff}}{{0.74}^2}+0.744$
$Z_{eff}=4.2039$
Hence, effective nuclear charge on oxygen is 4.2