Paulingskala

The Pauling scale, or Pauling electronegativity scale, is a relative measure of an atom's ability to attract shared electrons in a chemical bond. It was introduced by Linus Pauling in 1932 and remains one of the most widely used scales for comparing electronegativities in chemistry. The scale provides a qualitative ordering of elements rather than an absolute quantity.

The scale is derived from thermochemical data, particularly bond dissociation energies, and encodes the idea that differences in electronegativity influence bond strength. Fluorine is assigned the highest value on the scale, set at 3.98, and other elements are positioned relative to this anchor. The scale is dimensionless; it expresses relative, not intrinsic, electronegativity and reflects how strongly an atom tends to attract electrons in bonds within typical compounds. Common reference values include hydrogen about 2.20, carbon about 2.55, nitrogen about 3.04, oxygen about 3.44, and chlorine about 3.16.

Use and interpretation: larger differences in electronegativity between two bonded atoms imply greater bond polarity and partial charges, affecting molecular structure, reactivity, and acidity/basicity. The Pauling scale is especially influential in organic and inorganic chemistry for predicting bond character and trends across the periodic table.

Limitations: the scale is empirical and environment-dependent, varying with oxidation state and chemical context. It is not an intrinsic property measured directly. Other scales, such as Mulliken or Allred-Rochow, offer alternative definitions based on different physical quantities. The Pauling scale remains a practical tool for rapid assessments of relative electronegativity and bond polarity.

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