Data reference—Ionisation energies, electronegativity and Periodic Table

Ionisation-energy tables, Pauling electronegativities and the Periodic Table are evidence for explaining trends in bonding, periodicity and reactivity—not replacements for the explanation itself.

Quote the relevant comparison, then link it to nuclear charge, shielding, distance, electron attraction or bond polarity as appropriate. Check that the species and successive ionisation step match the question.

A larger electronegativity difference supports a more polar bond; a sudden jump in successive ionisation energies indicates that the next electron is being removed from an inner shell.

A table value alone does not explain a trend, and electronegativity is not the same quantity as ionisation energy.