A NEW SCALE OF ELECTRONEGATIVITY OF 54 ELEMENTS OF PERIODIC TABLE BASED ON POLARIZABILITY OF ATOMS

Abstract

A polarizability (α) based new scale of electronegativity (χ) is proposed. The basic algorithm is suggested by exploiting the fact that both polarizability and electronegativity are periodic properties and they are connected by an inverse relationship. Relying upon their express behavior along the periods of the periodic table, a general and straightforward relation between χ and α is suggested as χ = m(1/α)1/3 + c, where m and c are constants. The constants m and c are evaluated by least square fitting by plotting χ vs. (1/α)1/3 for each period separately. Thereafter, the suggested equation is used to evaluate the electronegativity, χ, of 54 elements from H to Xe in terms of least square fitted m and c, and a new set of atomic polarizabilities are computed by Ghosh and Biswas. The evaluated electronegativities exhibit periodicity of groups and periods and reproduce the silicon rule and the expected trend of variation of the electronegativities of d block transition metals. The evaluated electronegativities of the present semiempirical method are quite comparable with those computed by the rigorous mathematical method of Robles and Bartolotti. The efficacy of the new scale is also tested by computing the bond energy of a number of compounds. We have proposed a new formula relating the bond energy with the electronegativity difference. The proposed relation is given by D AB - 〈D AB 〉= 3.8866Δχ + 0.0422, where 〈D AA 〉 = (D AA D BB )1/2, Δχ represents the electronegativity difference, and D AA , D BB , and D AB are the bond energies of homonuclear A–A, B–B, and hetero-nuclear A–B molecules. A comparative study of bond energies evaluated through the proposed relation, determined experimentally, and evaluated through other relations is also furnished. It is demonstrated that the proposed relation of computing the bond energy in terms of Δχ yields good bond energy values. Results demonstrate that the new polarizability based empirical scale of electronegativity is a fairly successful venture.