The ionization enthalpy and electron gain enthalpy of an element or 275 and 86 kcal per mole. Electronegativity of the element on mulliken scale and p a u l i n g scale respectively are

The Electronegativity according to the Mullikan's scale is given by the formula

Electronegativity = (Ionisation Energy + Electron Affinity)/540

if Ionisation Energy & Electron Affinity(Electron Gain Enthalpy) are in KJ/mol

Electronegativity = (Ionisation Energy + Electron Affinity)/5.6

if Ionisation Energy & Electron Affinity(Electron Gain Enthalpy) are in Electron Volts(eV)

Mullikan's values = 2.8 * pauling values (the Ionisation Energy & Electron Affinity values must be given in electron volts(eV)).

This method is used when 2 of the 3 parameters used in the equation are known.