Compare two Pauling electronegativity values
Electronegativity describes an atom’s tendency to attract shared electron density in a chemical bond. Choose two elements with listed Pauling values to calculate the absolute difference, Δχ. The result keeps both values visible and adds a cautious classroom guide for mostly nonpolar covalent, polar covalent, or strongly ionic character. It does not turn that guide into a hard law.
For sodium and chlorine, the Pauling values are about 0.93 and 3.16, so the difference is 2.23 and the bond is commonly introduced as having strong ionic character. For carbon and hydrogen, the smaller difference supports a covalent description. These comparisons are useful starting points, but a compound’s actual bonding and structure contain more information than one subtraction.
How the difference is calculated
The order of element selection does not affect the answer because the calculator uses an absolute value: |χ₁ − χ₂|. A difference of zero means the selected values match, as in a bond between identical atoms. Increasing difference indicates increasing bond polarity within this scale and context. The page prints both source values before the subtraction so a transposed or unexpected element is easy to notice.
Only elements with a numerical Pauling value in the current table appear in the menus. Some noble gases and very heavy elements do not have a broadly used value on the same footing, so the tool does not fill those gaps with zero. Zero would imply a measured absence of electronegativity and would create a misleadingly large difference.
Read classification thresholds as guideposts
A common introductory guide labels differences below about 0.4 as mostly nonpolar covalent, from roughly 0.4 to below 1.7 as polar covalent, and larger differences as strong ionic character. Textbooks vary in their cutoffs, and compounds near a boundary should not be treated as though a tiny decimal change switches the underlying physics abruptly.
The guide describes bond character, not a complete compound type. Polyatomic ions contain covalent bonds internally while forming ionic compounds with counterions. Metallic bonding, coordination, resonance, formal charge, oxidation state, and three-dimensional structure can all alter how electron density is discussed. Use the difference to support an explanation, not to replace the rest of the chemical evidence.
Check the trend and selected scale
On the Pauling scale, fluorine is the most electronegative listed element. Values generally rise across a period and fall down a group, with important nuances. If a selected pair appears to violate an expected trend, first confirm the symbols and values printed in the result. Then check whether the comparison source uses Pauling, Mulliken, Allred–Rochow, or another electronegativity scale.
Values from different scales should not be subtracted directly. Even within a named scale, tables may differ slightly in rounding or coverage. This page uses one internally consistent Pauling table and rounds the displayed difference after calculation. Cite the table or scale when a formal assignment requires a specific numerical source.
Limits and private comparison
Electronegativity is a model-dependent chemical concept, not a directly isolated property that predicts every bond by itself. The result does not calculate percent ionic character, dipole moment, bond energy, molecular polarity, solubility, or reactivity. Molecular polarity also depends on geometry and whether individual bond dipoles cancel.
The values are calculated in the current browser tab. NexaCurrent does not upload the quantities, formulas, chemical names, element choices, or other information entered here, and no account is needed. Copying is a deliberate action after the answer and working are visible. Refreshing or leaving the page clears the current calculation, so keep a copied result if it is needed for later study.