Pauling's electronegativity

1. Pauling electronegativity
Dr. Mithil Fal Desai
Shree Mallikarjun and Shri Chetan Manju Desai College
Canacona Goa

2. Linus Pauling described electronegativity
as “the power of an atom in a molecule to
attract electrons to itself when combined
in a compound.”
Linus Pauling
Definition of Electronegativity
e-
e-
Atom A
Atom B
e-
e-

3. Calculating Electronegativity
A B
The factor 0.208 arises from the conversion
electronegativity values from Kcals to electron volt.

4. Calculating Electronegativity
A B
EA-B> EA-A or EB-B
EA-B(measured)> EA-B(theoretical)
Difference in the Bond Energies (Δ)
Δ = EA-B(measured) – EA-B(theoretical)
EA-B(theoretical) = energy for 100% covalent bond
EA-B(theoretical) = (EA-A X EB-B)1/2
Thus
Δ= EA-B(measured) – (EA-A X EB-B)½
δ+ δ-
If X(A) and X(B) are
electronegativity of individual
atoms A and B, respectively,
than
X(A) - X(B) = 0.1017(Δ)½ in kJ mol-1
X(A) - X(B) = 0.208 (Δ)½ in kcal mol-1

5. Periodic trend in Electronegativity
Pauling’s electronegativity values are
measured in electron volt (eV).

6. Summary
• F is most electronegative element
• If two element have similar(<1.7) electronegativity
values the bond is covalent or metallic.
• If two element have large (>1.7) difference in their
electronegativity values the bond is ionic
predominantly.
As Atomic number increases
• Electronegativity decreases down the group
• Electronegativity increases along the row

7. References
• Lee, J. D., (2018), Concise Inorganic Chemistry, Fifth Edition, New
Delhi, Wiley India.
• Huheey, J. E., Keiter, E. A., Keiter, R. L., Medhi, O. K., (2019) Inorganic
Chemistry: Principle of structure and reactivity, Fourth Edition, Noida,
Pearson Education India.
• Atkins, P., Overton T., Rourke, J., Weller, M., Armstrong F., (2006)
Shriver and Atkin’s Inorganic Chemistry, Fourth Edition, Great Britain,
Oxford University Press.