What is the calculated Mulliken scale electronegativity of an unknown element if its first ionizatio — Periodic Table and Periodicity Chemistry Question

💡 Solution & Explanation

The Mulliken scale defines electronegativity as the simple arithmetic average of the Ionization Potential (IP) and Electron Affinity (EA) when both are expressed in $\text{eV/atom}$. $EN_M = \frac{IP + EA}{2}$. Substituting the values: $EN_M = \frac{14.5 + 3.5}{2} = \frac{18.0}{2} = 9$.