Paulingskálán

Paulingskálán is a term originating from the field of chemistry, specifically related to the concept of electronegativity. It refers to a scale developed by Linus Pauling to quantify the tendency of an atom to attract a bonding pair of electrons. Pauling's scale is the most widely used electronegativity scale.

Electronegativity is a fundamental property that influences the type of chemical bond formed between atoms. When two atoms with significantly different electronegativities bond, the bond tends to be polar covalent or ionic. Conversely, if the electronegativities are similar, the bond is typically nonpolar covalent. Pauling assigned numerical values to elements based on their electronegativity, with fluorine, the most electronegative element, being assigned a value of 4.0. Other elements receive values relative to fluorine.

The Paulingskálán is not derived from direct experimental measurements of electron attraction but is calculated based on the bond energies of various compounds. Specifically, Pauling compared the energy of a bond between two different atoms to the average of the energies of the bonds between two atoms of the same element. The difference in bond energy is attributed to the ionic character of the bond, which in turn reflects the difference in electronegativity. While a useful and widely adopted system, the Paulingskálán is an empirical scale and has limitations, particularly when dealing with complex molecules or elements with unusual bonding characteristics. Other electronegativity scales, such as the Mulliken and Allred-Rochow scales, exist and are based on different theoretical approaches.