How this instrument works
Electronegativity measures how strongly an atom attracts the electrons in a chemical bond toward itself. It isn't a directly measurable physical quantity like mass or charge — it's a relative scale, built by comparing bond energies and behavior across many compounds. The most widely used version, developed by Linus Pauling in the 1930s, assigns fluorine the highest value (3.98) as the most electronegative element, with values generally decreasing as you move left and down the periodic table toward metals like cesium (0.79).
This lookup uses a curated table of Pauling-scale values (Allred's 1961 revision, as reproduced in the CRC Handbook of Chemistry and Physics) covering 42 elements spanning the main groups and the first row of transition metals. Electronegativity generally increases left-to-right across a period, as the nucleus's pull on the outer electrons strengthens, and decreases top-to-bottom within a group, as those electrons sit farther from the nucleus and are increasingly shielded by inner electron shells.
The table intentionally omits helium, neon, and argon — not an oversight. Electronegativity is defined through how an atom behaves in chemical bonds, and no standard, citable Pauling-scale value exists for these three because they form no known stable compounds to derive one from. Krypton and xenon, which do form real (if unusual) compounds, remain in the table with citable values around 3.00 and 2.60 respectively. If you need a broader 50-element set that includes He, Ne, and Ar, this site's atomic mass lookup covers all of them, since atomic weight — unlike electronegativity — is well-defined for every element regardless of how reactive it is.
- Open the 'Element' dropdown and select the element you need — it's listed as symbol and full name, e.g. 'O — Oxygen.'
- Read 'Electronegativity (Pauling scale)' below — it updates the instant you change the element.
- Use the value in bond-polarity comparisons: subtract two elements' electronegativities to get ΔEN for formulas like percent ionic character.
- If the element you need isn't listed, it's most likely helium, neon, or argon — see the FAQ below for why those three are excluded.
Worked example — comparing oxygen and fluorine
Select 'O — Oxygen' from the dropdown. The result reads 3.44 on the Pauling scale — a well-known anchor value, and the second-highest electronegativity of any element in this table.
Now switch to 'F — Fluorine' instead. The result reads 3.98 — the single highest value on the entire Pauling scale, which is why fluorine sits at the top-right corner of the periodic table's electronegativity trend and forms the most polar bonds with almost every other element it reacts with.
Questions
Why are helium, neon, and argon missing from this list?
Because electronegativity is defined by how an atom behaves in a chemical bond, and He, Ne, and Ar form essentially no stable compounds to measure that behavior from — there's no citable, standard Pauling-scale value for them the way there is for reactive elements. This is a deliberate scope decision, not a gap in the data: the table covers exactly the 42 elements that have a real, sourced Pauling electronegativity, and stops there rather than guessing at values for elements that don't chemically bond.
Why do krypton and xenon have values if helium, neon, and argon don't?
Because krypton and xenon actually form real, if unusual, chemical compounds — xenon fluorides, oxides, and related species, for example — which gives chemists real bonding behavior to derive a Pauling-scale value from. Helium, neon, and argon are essentially chemically inert under any normal conditions, so no analogous compounds exist to calculate an electronegativity from, which is why they're excluded while their heavier noble-gas cousins are included at roughly 3.00 and 2.60 respectively.
Is Pauling's scale the only electronegativity scale?
No — it's the most widely taught, but chemists also use the Mulliken scale (based on ionization energy and electron affinity), the Allred-Rochow scale (based on effective nuclear charge), and others. They rank elements similarly but aren't numerically identical, since each is derived from a different underlying physical definition of 'attraction for electrons.' This lookup specifically uses Pauling-scale values, which is the convention assumed by formulas like percent ionic character that also appear on this site.
Does a higher electronegativity always mean a more reactive element?
No — those are different properties. Electronegativity measures how strongly an atom pulls on electrons within a bond it's already formed; reactivity depends on many other factors too, including how easily the atom gets into a bond in the first place. Fluorine is both highly electronegative and highly reactive, but noble gases sit near several fairly electronegative elements on the periodic table while barely reacting at all, which shows the two properties don't rise and fall together.
How is electronegativity different from electron affinity?
Electron affinity is the energy released or absorbed when a single, isolated gas-phase atom gains one electron — a specific, directly measurable thermodynamic quantity. Electronegativity is a broader, relative scale describing how an atom pulls on electrons while already bonded to another atom, and it's derived from bond energies across many compounds rather than one isolated-atom measurement. The two trends correlate loosely across the periodic table but aren't the same number and don't always rank elements identically.