Electronegativity Calculator

Calculate the electronegativity difference between two elements and see whether the resulting bond is nonpolar covalent, polar covalent, or ionic.

🔗 Electronegativity Calculator
Electronegativity Difference (ΔEN)
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Bond Type
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Values Used
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Bond Type Scale

🔗 What is the Electronegativity Calculator?

The Electronegativity Calculator finds the difference in Pauling-scale electronegativity between two atoms and classifies the resulting chemical bond as nonpolar covalent, polar covalent, or ionic. Electronegativity measures how strongly an atom pulls shared electrons toward itself in a bond, and the difference between two atoms' electronegativities (delta EN) is one of the most reliable predictors of what kind of bond will form between them.

This calculator has a built-in lookup table of Pauling-scale electronegativity values for over 50 common elements, so you can simply pick two elements from a dropdown instead of memorising or looking up values elsewhere. It also supports entering a custom electronegativity value directly, useful for less common elements, hypothetical scenarios, or checking a value from a different reference table.

A common point of confusion is treating the nonpolar, polar, and ionic categories as sharp, absolute boundaries. In reality, chemical bonding exists on a continuous spectrum from perfectly covalent (equal electron sharing) to perfectly ionic (complete electron transfer), and the thresholds of 0.4 and 1.7 are teaching conventions, not fundamental physical laws. A bond right at the edge, like carbon-hydrogen at 0.35, should be understood as borderline rather than definitively one category or the other.

Electronegativity difference has real predictive power across chemistry: it explains why water is a bent, polar molecule with hydrogen bonding capability, why table salt (NaCl) is an ionic solid rather than a molecular gas, and why organic molecules built mostly from carbon and hydrogen are relatively nonpolar and insoluble in water. This calculator makes checking that difference and its classification instant.

📐 Formula

ΔEN  =  |EN1 − EN2|
ΔEN = electronegativity difference (Pauling scale, dimensionless)
EN1, EN2 = Pauling electronegativity of each atom
ΔEN < 0.4: nonpolar covalent
0.4 ≤ ΔEN ≤ 1.7: polar covalent
ΔEN > 1.7: ionic

📖 How to Use This Calculator

Steps

1
Choose the first element or enter a custom value - select an element from the built-in Pauling-scale table, or switch to Custom to type your own electronegativity value.
2
Choose the second element or enter a custom value - repeat the same choice for the second atom in the bond.
3
Click Calculate to see the electronegativity difference, the bond type classification, and where it falls on the scale diagram.

💡 Example Calculations

Example 1 — Hydrogen chloride (H-Cl)

H (EN = 2.20) and Cl (EN = 3.16).

1
ΔEN = |2.20 − 3.16| = 0.96
2
0.4 ≤ 0.96 ≤ 1.7, so the bond is classified as polar covalent.
ΔEN = 0.96, Bond type = Polar covalent.
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Example 2 — Sodium chloride (Na-Cl)

Na (EN = 0.93) and Cl (EN = 3.16).

1
ΔEN = |0.93 − 3.16| = 2.23
2
2.23 > 1.7, so the bond is classified as ionic.
ΔEN = 2.23, Bond type = Ionic.
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Example 3 — Carbon-hydrogen (C-H)

C (EN = 2.55) and H (EN = 2.20).

1
ΔEN = |2.55 − 2.20| = 0.35
2
0.35 < 0.4, so the bond is classified as nonpolar covalent.
ΔEN = 0.35, Bond type = Nonpolar covalent.
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Example 4 — Cesium fluoride (Cs-F)

Cs (EN = 0.79) and F (EN = 3.98).

1
ΔEN = |0.79 − 3.98| = 3.19
2
3.19 > 1.7, so the bond is classified as ionic, one of the most ionic bonds possible.
ΔEN = 3.19, Bond type = Ionic.
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❓ Frequently Asked Questions

What is electronegativity?+
Electronegativity is a measure of how strongly an atom attracts shared electrons toward itself within a chemical bond. It is a relative, dimensionless quantity most commonly expressed on the Pauling scale, where fluorine has the highest value (3.98) of any element and francium and cesium have among the lowest (about 0.79).
What is the Pauling scale?+
The Pauling scale, developed by chemist Linus Pauling in 1932, assigns each element a numerical electronegativity value based on bond energy differences between different atom pairs. It remains the most widely used electronegativity scale in chemistry education and research, typically ranging from about 0.7 to 4.0 across the periodic table.
How do you calculate electronegativity difference?+
Electronegativity difference (delta EN, or Δχ) is calculated as the absolute value of the difference between the two atoms' Pauling electronegativity values: delta EN = |EN1 - EN2|. Since it uses an absolute value, the order in which you subtract the two values does not affect the result.
What electronegativity difference makes a bond ionic?+
By the widely used convention, a delta EN greater than 1.7 classifies a bond as ionic. This threshold is not an exact physical boundary, since bonding is really a continuous spectrum from fully covalent to fully ionic, but 1.7 corresponds roughly to the point where a bond is considered to have more than 50% ionic character.
What electronegativity difference makes a bond polar covalent?+
A delta EN between 0.4 and 1.7 (inclusive of 1.7) classifies a bond as polar covalent, meaning electrons are shared unequally between the two atoms, creating partial positive and negative charges (a dipole) without fully transferring an electron. Most bonds between different nonmetal elements fall into this category.
What electronegativity difference makes a bond nonpolar covalent?+
A delta EN below 0.4 classifies a bond as nonpolar covalent, meaning electrons are shared essentially equally between the two atoms. Bonds between identical atoms (like H-H or Cl-Cl, delta EN = 0) are always perfectly nonpolar, and bonds between atoms of similar electronegativity, like carbon and hydrogen, are treated as nonpolar in practice.
Why is carbon-hydrogen (C-H) considered a nonpolar bond?+
Carbon's electronegativity is 2.55 and hydrogen's is 2.20, giving a delta EN of 0.35, just below the standard 0.4 nonpolar threshold. This is why C-H bonds, which make up the backbone of organic chemistry, are conventionally treated as essentially nonpolar, even though carbon is technically slightly more electronegative than hydrogen.
Is sodium chloride (NaCl) ionic or covalent?+
Sodium's electronegativity is 0.93 and chlorine's is 3.16, giving a delta EN of 2.23, well above the 1.7 ionic threshold. This confirms that NaCl is classified as an ionic compound, consistent with sodium chloride's well-known ionic crystal structure and properties like high melting point and electrical conductivity when molten or dissolved.
Does a high electronegativity difference always mean the compound will exist?+
No. Electronegativity difference predicts the character of a bond that does form, not whether a stable compound will actually exist between two elements. Other factors, like atomic size, oxidation states, and overall thermodynamic stability, also determine whether a real compound forms and in what ratio.
Which element has the highest electronegativity?+
Fluorine has the highest Pauling electronegativity of any element, at 3.98, making it the most electron-attracting element on the periodic table. This is why fluorine almost always ends up with a partial or full negative charge in any bond it forms, and why HF, despite hydrogen and fluorine being adjacent-period nonmetals, has a fairly large delta EN of about 1.78.
Which elements have the lowest electronegativity?+
Cesium and francium have among the lowest Pauling electronegativity values, around 0.79, making them the most willing to give up electrons in a bond. This is consistent with their position at the bottom-left of the periodic table, in group 1, where electronegativity is lowest across the entire periodic table.
Tags: Electronegativity Calculator Pauling Scale Calculator Bond Polarity Calculator Ionic vs Covalent Bond Electronegativity Difference Chemistry Calculator Formula Free Online

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What is electronegativity?

Electronegativity is a measure of how strongly an atom attracts shared electrons toward itself within a chemical bond. It is a relative, dimensionless quantity most commonly expressed on the Pauling scale, where fluorine has the highest value (3.98) of any element and francium and cesium have among the lowest (about 0.79).

What is the Pauling scale?

The Pauling scale, developed by chemist Linus Pauling in 1932, assigns each element a numerical electronegativity value based on bond energy differences between different atom pairs. It remains the most widely used electronegativity scale in chemistry education and research, typically ranging from about 0.7 to 4.0 across the periodic table.

How do you calculate electronegativity difference?

Electronegativity difference (delta EN, or Δχ) is calculated as the absolute value of the difference between the two atoms' Pauling electronegativity values: delta EN = |EN1 - EN2|. Since it uses an absolute value, the order in which you subtract the two values does not affect the result.

What electronegativity difference makes a bond ionic?

By the widely used convention, a delta EN greater than 1.7 classifies a bond as ionic. This threshold is not an exact physical boundary, since bonding is really a continuous spectrum from fully covalent to fully ionic, but 1.7 corresponds roughly to the point where a bond is considered to have more than 50% ionic character.

What electronegativity difference makes a bond polar covalent?

A delta EN between 0.4 and 1.7 (inclusive of 1.7) classifies a bond as polar covalent, meaning electrons are shared unequally between the two atoms, creating partial positive and negative charges (a dipole) without fully transferring an electron. Most bonds between different nonmetal elements fall into this category.

What electronegativity difference makes a bond nonpolar covalent?

A delta EN below 0.4 classifies a bond as nonpolar covalent, meaning electrons are shared essentially equally between the two atoms. Bonds between identical atoms (like H-H or Cl-Cl, delta EN = 0) are always perfectly nonpolar, and bonds between atoms of similar electronegativity, like carbon and hydrogen, are treated as nonpolar in practice.

Why is carbon-hydrogen (C-H) considered a nonpolar bond?

Carbon's electronegativity is 2.55 and hydrogen's is 2.20, giving a delta EN of 0.35, just below the standard 0.4 nonpolar threshold. This is why C-H bonds, which make up the backbone of organic chemistry, are conventionally treated as essentially nonpolar, even though carbon is technically slightly more electronegative than hydrogen.

Is sodium chloride (NaCl) ionic or covalent?

Sodium's electronegativity is 0.93 and chlorine's is 3.16, giving a delta EN of 2.23, well above the 1.7 ionic threshold. This confirms that NaCl is classified as an ionic compound, consistent with sodium chloride's well-known ionic crystal structure and properties like high melting point and electrical conductivity when molten or dissolved.

Does a high electronegativity difference always mean the compound will exist?

No. Electronegativity difference predicts the character of a bond that does form, not whether a stable compound will actually exist between two elements. Other factors, like atomic size, oxidation states, and overall thermodynamic stability, also determine whether a real compound forms and in what ratio.

Which element has the highest electronegativity?

Fluorine has the highest Pauling electronegativity of any element, at 3.98, making it the most electron-attracting element on the periodic table. This is why fluorine almost always ends up with a partial or full negative charge in any bond it forms, and why HF, despite hydrogen and fluorine being adjacent-period nonmetals, has a fairly large delta EN of about 1.78.

Which elements have the lowest electronegativity?

Cesium and francium have among the lowest Pauling electronegativity values, around 0.79, making them the most willing to give up electrons in a bond. This is consistent with their position at the bottom-left of the periodic table, in group 1, where electronegativity is lowest across the entire periodic table.

📌 Quick Tips

💡Electronegativity difference (delta EN) is always calculated as an absolute value, so it does not matter which element you enter first.
💡A delta EN below 0.4 is considered nonpolar covalent, between 0.4 and 1.7 is polar covalent, and above 1.7 is considered ionic, these thresholds are widely taught conventions, not sharp physical boundaries.
💡Carbon-hydrogen bonds (delta EN = 0.35) fall just under the nonpolar threshold, which is why C-H bonds are usually treated as essentially nonpolar in organic chemistry.
💡Fluorine has the highest electronegativity of any element (3.98), while cesium and francium have among the lowest (about 0.79), so a Cs-F bond has one of the largest delta EN values possible.
💡Real chemical bonding is a spectrum, not three separate boxes, so a delta EN just below or above a threshold (like the C-H example) should be treated as borderline rather than a hard cutoff.