All calculatorsElectronegativity Calculator
Compare electronegativities (χ) and bond polarity for two elements. Uses the Pauling scale by default. Computes Δχ, classifies bond type (nonpolar, polar, ionic), estimates % ionic character, and shows dipole direction. Optional mini chart visualizes χ and Δχ. Advanced mode supports the Allred–Rochow scale.
Background
Electronegativity (χ) describes an atom’s tendency to attract electrons in a bond. The Pauling scale is standard in general chemistry. A rule of thumb: Δχ < 0.4 (nonpolar covalent), 0.4–1.7 (polar covalent), > 1.7 (ionic).
How to use this calculator
- Input: Type symbol (Na), name (Sodium), or atomic number (11) for both A and B.
- Overrides: You can enter χ(A) and χ(B) manually if desired.
- Advanced: Switch to Allred–Rochow (AR) scale; we’ll use an AR table where available and fall back to Pauling if not.
- Output: χ(A), χ(B), Δχ, bond classification, dipole direction, % ionic estimate, and an optional mini chart.
- Classification guide: Δχ < 0.4 = nonpolar covalent; 0.4–1.7 = polar covalent; > 1.7 = ionic.
- % ionic estimate: \( \%\,\text{ionic} \approx \bigl(1 - e^{-0.25\,(\Delta\chi)^2}\bigr)\times 100 \).
Examples
C–H
χ(C)=2.55, χ(H)=2.20 → Δχ=0.35 → nonpolar covalent (slightly polar), dipole C←H (very small), % ionic ≈ 3%.
Na–Cl
χ(Na)=0.93, χ(Cl)=3.16 → Δχ=2.23 → ionic, dipole Na→Cl, % ionic ≈ 63% (empirical estimate).
H–F
χ(H)=2.20, χ(F)=3.98 → Δχ=1.78 → strongly polar covalent (borderline ionic), dipole H→F, % ionic ≈ 66%.
Frequently Asked Questions
Q: Which electronegativity scale is used?
Pauling by default. Advanced mode lets you choose Allred–Rochow.
Q: How accurate is the % ionic character?
It’s an empirical estimate from Δχ; useful for trends rather than exact values.
Q: Does Δχ alone decide bond type?
Δχ is a strong indicator, but lattice energies and environment also matter. Classification here follows standard undergrad guidelines.
