Question

For univalent elements, the average value of first ionization potential and first electron affinity is equal to its:

• A. polarising power
• B. covalent radius
• C. electronegativity
• D. dipole moment

Answer 1

Answer: (C)

electronegativity

For univalent elements, the average value of first ionization potential and first electron affinity is equal to its electronegativity.
$\text{Electronegativity}=\frac{\text{Ionization potential}+\text{Electron affinity}}{2}$
This is the formula on Mulliken's scale. On Pauling scale, the formula is
$\text{Electronegativity}=\frac{\text{Ionization potential}+\text{Electron affinity}}{5.6}$
when ionization potential and electron affinity values are in eV.
$\text{Electronegativity}=\frac{\text{Ionization potential}+\text{Electron affinity}}{2\times 62.5}$
when ionization potential and electron affinity values are in kcal/mol.