7.1 Measurement of Electronegativity

2.1 Modern Periodic Table
2.2 Merits of Long Form of Periodic Table Over Mendeleef’s Periodic Table

3.1 p-Block Elements
3.2 d-Block Elements
3.3 f-Block Elements

4.1 Effective Nuclear Charge

5.1 Factor Affecting Ionization Potential
5.2 Trends in Ionization Potential
5.3 Ionization Potential of Transition Elements
5.4 Application of Ionization Potential

7.1 Measurement of Electronegativity
7.2 Application of Electronegativity

If two atoms, A and B, having different electronegativity values get bonded to form a molecule AB, then the bond between A and B in A-B will have both covalent and ionic properties.

The difference in electronegativity of atoms A and B is given by,$${X_A} - {X_B} = 0.208\sqrt {{\Delta _{A - B}}} $$where,

$X_A$ = Electronegativity of atom A

$X_B$ = Electronegativity of atom B

${\Delta _{A - B}} = D - {E_{A - B}}$

$D$= Observed bond energy

$E_{A-B}$= Bond energy of pure covalent bond of $A-B$$${E_{A - B}} = \frac{{{E_{A - A}} - {E_{B - B}}}}{2}$$

Mulliken suggested that the value of electronegativity of an element is an average of the value of its ionization potential (I.P.) and electron affinity (E.A.).$${X_M} = \frac{{I.P. + E.A.}}{2}(ineV)$$$${X_P} = \frac{{{X_M}}}{{2.8}} = \frac{{I.P. + E.A.}}{{5.6}}(ineV)$$where,

$X_M$ = Electronegativity value as given by Mulliken

$X_P$ = Electronegativity value as given by Pauling