Consider the following statements for Allred- Rochow electronegativity (χ_AR):

i. χ_AR is directly proportional to Z_eff.
ii. χ_AR is inversely proportional to Z_eff
iii. χ_AR is inversely proportional to r (covalent)
iv. χ_AR is inversely proportional to r²(covalent)
The correct statements are

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Correct option is A

​Allred and Rochow chose as a measure of electronegativity of an atom the electrostatic force exerted by the effective nuclear charge Z_eff on the valence electrons. The latter are assumed to reside at a distance from the nucleus equal to the covalent radius, r_cov, of the atom. Equation gives the method of calculating values of the Allred–Rochow electronegativity.

$$\chi^{AR} = \left( 3590 \times \frac{Z_{\text{eff}}}{r_{\text{cov}}^2} \right) + 0.744 \quad \text{where} \quad r_{\text{cov}} \, \text{is in pm}$$