3.1.4—The differences in Pauling electronegativity

Use the supplied Pauling electronegativity values in a fixed sequence: compare the two bonded atoms, determine the size of the difference, and then classify the bond using the stated syllabus rule. Similar values support equal or nearly equal sharing; a larger difference means the bonding pair is attracted more strongly towards one atom.

A small difference is consistent with a non-polar covalent bond, an intermediate difference with a polar covalent bond, and a sufficiently large difference with ionic bonding under the assessed classification. In a polar covalent bond, show the partial-charge direction towards the more electronegative atom rather than describing full electron transfer.

The electronegativity difference predicts how unevenly the bonding electrons are shared: the greater the difference, the greater the unequal attraction and bond polarity. Keep the bond-level conclusion tied to the supplied values and the stated classification boundary.

Do not invent a universal numerical cutoff when values are not supplied, confuse bond polarity with the overall polarity of a molecule, or treat a polar covalent bond as complete ionic electron transfer. Covalent character in ionic compounds is outside the assessed scope here.