Electronegativity Calculator

Electronegativity and Bond Polarity Explained

Electronegativity is the tendency of an atom to attract the shared electron pair in a chemical bond toward itself. Linus Pauling defined the scale in 1932 based on bond dissociation energies: if a bond A–B releases more energy than would be expected from purely covalent A–A and B–B bonds, that extra energy reflects an ionic resonance stabilization caused by the electronegativity difference.

The electronegativity difference (ΔEN) between bonded atoms determines bond character. At ΔEN = 0, the bond is purely nonpolar covalent. As ΔEN increases, the bond becomes increasingly polar — electrons are pulled toward the more electronegative atom. At approximately ΔEN ≥ 1.7, the bond has more than 50% ionic character and is classified as ionic.

Bond Type Classification by ΔEN

Electronegativity Trends in the Periodic Table

Electronegativity increases across a period because nuclear charge increases while atomic radius decreases — bonding electrons experience a stronger pull toward the nucleus. It decreases down a group because atomic radius increases, placing bonding electrons farther from the increasingly shielded nuclear charge. Fluorine at the top-right corner of the periodic table has the highest EN (3.98). Cesium and francium at the bottom-left have the lowest (<0.8).

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