Question

Covalent radius of F is 0.72 A${}^o$. Calculate its Allred-Rochow's electronegativity to nearest integer

Answer 1

The Allred-Rochow electronegativity formula is $\chi =\frac{0.359Z}{r^2}+0.744$

Here, $Z$ is the effective nuclear charge and $r$ is the atomic radius.

Substitute values in the above expression.

$\chi =\frac{0.359\times 5.2}{{0.72}^2}+0.744=4.345$

Hence, the electronegativity of fluorine on the Allred-Rochow scale is $\mathrm{4.345.}$

So, the correct answer is 4.