Electronegativity of the elements

Electronegativity is how strongly an atom pulls the shared electrons of a bond towards itself. These are Pauling values, a dimensionless scale worked out from bond energies, on which fluorine sits near 4. The values are PubChem’s, published by the US National Institutes of Health. It gives one for 95 of the 118 elements; the rest are hatched in the table below rather than coloured as if they were zero.

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H 2.2, hydrogen He no value, helium Li 0.98, lithium Be 1.57, beryllium B 2.04, boron C 2.55, carbon N 3.04, nitrogen O 3.44, oxygen F 3.98, fluorine Ne no value, neon Na 0.93, sodium Mg 1.31, magnesium Al 1.61, aluminium Si 1.9, silicon P 2.19, phosphorus S 2.58, sulfur Cl 3.16, chlorine Ar no value, argon K 0.82, potassium Ca 1, calcium Sc 1.36, scandium Ti 1.54, titanium V 1.63, vanadium Cr 1.66, chromium Mn 1.55, manganese Fe 1.83, iron Co 1.88, cobalt Ni 1.91, nickel Cu 1.9, copper Zn 1.65, zinc Ga 1.81, gallium Ge 2.01, germanium As 2.18, arsenic Se 2.55, selenium Br 2.96, bromine Kr 3, krypton Rb 0.82, rubidium Sr 0.95, strontium Y 1.22, yttrium Zr 1.33, zirconium Nb 1.6, niobium Mo 2.16, molybdenum Tc 1.9, technetium Ru 2.2, ruthenium Rh 2.28, rhodium Pd 2.2, palladium Ag 1.93, silver Cd 1.69, cadmium In 1.78, indium Sn 1.96, tin Sb 2.05, antimony Te 2.1, tellurium I 2.66, iodine Xe 2.6, xenon Cs 0.79, caesium Ba 0.89, barium La 1.1, lanthanum Ce 1.12, cerium Pr 1.13, praseodymium Nd 1.14, neodymium Pm no value, promethium Sm 1.17, samarium Eu no value, europium Gd 1.2, gadolinium Tb no value, terbium Dy 1.22, dysprosium Ho 1.23, holmium Er 1.24, erbium Tm 1.25, thulium Yb no value, ytterbium Lu 1.27, lutetium Hf 1.3, hafnium Ta 1.5, tantalum W 2.36, tungsten Re 1.9, rhenium Os 2.2, osmium Ir 2.2, iridium Pt 2.28, platinum Au 2.54, gold Hg 2, mercury Tl 1.62, thallium Pb 2.33, lead Bi 2.02, bismuth Po 2, polonium At 2.2, astatine Rn no value, radon Fr 0.7, francium Ra 0.9, radium Ac 1.1, actinium Th 1.3, thorium Pa 1.5, protactinium U 1.38, uranium Np 1.36, neptunium Pu 1.28, plutonium Am 1.3, americium Cm 1.3, curium Bk 1.3, berkelium Cf 1.3, californium Es 1.3, einsteinium Fm 1.3, fermium Md 1.3, mendelevium No 1.3, nobelium Lr 1.3, lawrencium Rf no value, rutherfordium Db no value, dubnium Sg no value, seaborgium Bh no value, bohrium Hs no value, hassium Mt no value, meitnerium Ds no value, darmstadtium Rg no value, roentgenium Cn no value, copernicium Nh no value, nihonium Fl no value, flerovium Mc no value, moscovium Lv no value, livermorium Ts no value, tennessine Og no value, oganesson

How it changes across a period and down a group

Across a period electronegativity rises. Each step to the right adds a proton to the nucleus and an electron to the same shell, and electrons in one shell screen each other poorly, so the bonding electrons feel a steadily stronger pull. Period 2 shows it cleanly, rising at every step from lithium’s 0.98 to fluorine’s 3.98.

Down a group it falls. Each period adds a shell, so the bonding electrons sit further from the nucleus behind more inner electrons, and the extra nuclear charge does not make up for the distance. Group 17 runs 3.98, 3.16, 2.96, 2.66 from fluorine to iodine.

The two trends meet at the corners of the table: the most electronegative elements are at the top right, fluorine then oxygen, and the least are at the bottom left, francium and caesium.

The transition metals follow neither trend closely. Their values bunch between 1.22 and 2.54, and in 11 places a transition metal is more electronegative than the one above it: gold, at 2.54, is well above silver, at 1.93.

Extremes and exceptions

Highest and lowest

• Fluorine, 3.98
• Oxygen, 3.44
• Chlorine, 3.16
• Francium, 0.7
• Caesium, 0.79
• Rubidium, 0.82

The three most and the three least electronegative elements PubChem gives a value for.

Rising down a group instead of falling

• Aluminium to gallium: 1.61 to 1.81
• Silicon to germanium: 1.9 to 2.01
• Tin to lead: 1.96 to 2.33
• Barium to radium: 0.89 to 0.9

Gallium and germanium come straight after the first row of the d-block, whose ten extra protons are poorly shielded by the d electrons added with them, so they hold bonding electrons more tightly than aluminium and silicon above them. Lead comes after the lanthanides as well, where the same effect is stronger. Radium’s single-decimal value is within rounding of barium’s.

The 95 elements with a value, ranked

Equal values share a rank, marked with =.

No value in PubChem’s table, so not ranked: helium, neon, argon, promethium, europium, terbium, ytterbium, radon, rutherfordium, dubnium, seaborgium, bohrium, hassium, meitnerium, darmstadtium, roentgenium, copernicium, nihonium, flerovium, moscovium, livermorium, tennessine and oganesson.

The values are facts and free to use; this table’s selection and presentation are © 2026 ScienceQuest.

Caveats

• Helium, neon and argon have no Pauling value, while krypton and xenon do. The scale is worked out from the energies of the bonds an element forms, and the three lighter noble gases form no compounds that are stable at ordinary temperatures. Radon has no value in PubChem’s table either.
• Francium’s 0.7 is the lowest figure here and the least certain. It is Linus Pauling’s estimate, never refined by measurement, and francium is slightly harder to ionise than caesium, which suggests caesium is really the less electronegative of the two.
• Four lanthanides, promethium, europium, terbium and ytterbium, have no value in PubChem’s table although their neighbours do. That is a gap in the table, not a statement that they have no electronegativity.
• Every actinide from americium to lawrencium is listed at the same 1.3, to one decimal place, so the table cannot tell them apart. Treat the differences between them as unknown rather than zero.
• Nothing past lawrencium has a value: those elements have been made only a few atoms at a time, too few to measure a bond.
• Scales differ. Mulliken’s and Allen’s give different numbers for the same element, and Allen’s gives the lighter noble gases values too, argon’s 3.242 among them, so figures from different scales should not be mixed in one comparison.

See also

• The interactive periodic table, with every element’s details
• VSEPR molecular geometry, where bond polarity comes into it
• All the elements, each with its own page of data