E

Electronegativity

Pauling scale: χ; F = 3.98; O = 3.44; N = 3.04; C = 2.55; H = 2.20
Quick Reference
Formula / NotationPauling scale: χ; F = 3.98; O = 3.44; N = 3.04; C = 2.55; H = 2.20
Also Known AsEN, Pauling electronegativity, electron attraction, χ (chi)

What is Electronegativity?

A measure of an atom's ability to attract shared electrons toward itself in a covalent bond. The Pauling scale is most commonly used. Fluorine has the highest electronegativity (4.0). Electronegativity increases across periods and decreases down groups in the periodic table.

Formula & Notation

Pauling scale: χ; F = 3.98; O = 3.44; N = 3.04; C = 2.55; H = 2.20

Other Names / Synonyms: EN, Pauling electronegativity, electron attraction, χ (chi)

Properties & Characteristics

Electronegativity is the tendency of an atom to attract shared electron pairs toward itself in a covalent bond. The Pauling scale is the most common; the Mulliken and Allred-Rochow scales are alternatives. EN increases across a period (increasing nuclear charge) and decreases down a group (increasing distance and shielding). The difference in EN (ΔEN) between bonded atoms determines bond polarity: ΔEN > 1.7 → ionic character dominant; ΔEN < 0.5 → essentially nonpolar covalent.

Uses & Applications

Electronegativity values predict bond polarity, partial charges, dipole moments, and the type of bonding (ionic vs. covalent). They are used in rationalising reaction mechanisms (nucleophilicity, electrophilicity), acid strength, and oxidation state assignments.

Safety Information

High EN differences indicate strong polar bonds or ionic character; dissolution of ionic compounds in water can produce corrosive or toxic ion concentrations. Fluorine (highest EN) forms explosively reactive compounds with most elements.

Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.

Key Facts

Term Electronegativity
Formula Pauling scale: χ; F = 3.98; O = 3.44; N = 3.04; C = 2.55; H = 2.20
Synonyms EN, Pauling electronegativity, electron attraction, χ (chi)

Frequently Asked Questions

A measure of an atom's ability to attract shared electrons toward itself in a covalent bond. The Pauling scale is most commonly used. Fluorine has the highest electronegativity (4.0). Electronegativity increases across periods and decreases down groups in the periodic table.

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