Electronegativity Calculator

Calculate electronegativity difference between two elements and determine the type of chemical bond formed: nonpolar covalent, polar covalent, or ionic.

Enter first element symbol (e.g., Na, H, O)

Enter second element symbol (e.g., Cl, O, S)

ΔEN = |EN₁ - EN₂|. ΔEN < 0.4 = nonpolar, 0.4-1.7 = polar, >1.7 = ionic
NaCl: EN(Na) = 0.93, EN(Cl) = 3.16, ΔEN = 2.23 → Ionic bond. HF: EN(H) = 2.20, EN(F) = 3.98, ΔEN = 1.78 → Ionic (borderline).

What is electronegativity?

Electronegativity measures an atom's ability to attract shared electrons in a chemical bond. The Pauling scale (1.0-4.0) is most common: fluorine (3.98) is most electronegative; francium (0.7) is least. Higher electronegativity means stronger electron attraction in bonds.

How do you predict bond type from electronegativity difference?

ΔEN = |EN₁ - EN₂| predicts bond character: ΔEN < 0.4 = nonpolar covalent (equal sharing, e.g., H-H); 0.4-1.7 = polar covalent (unequal sharing, e.g., H-Cl); ΔEN > 1.7 = ionic (electron transfer, e.g., NaCl). Larger ΔEN means more polar/ionic character.

What is the difference between electronegativity and electron affinity?

Electronegativity is a relative measure of atom behavior in bonds (theoretical scale); electron affinity is the actual energy released when an atom gains an electron (experimental, kJ/mol). They're related but not identical. EA measures a single process; EN describes bond behavior.

Which bonds have partial charges?

In polar covalent bonds, the more electronegative atom gains partial negative charge (δ⁻) while the less electronegative atom has partial positive charge (δ⁺). Water (H-O-H): oxygen (3.44) > hydrogen (2.20), so O is δ⁻ and H is δ⁺. This polarity enables hydrogen bonding.