Difference Between Electronegativity and Electron Affinity

The main key difference between electronegativity and electron affinity is that electronegativity is the property associated with the attracting ability of electron towards an atom. As against, electron affinity is associated with the release of energy when an electron is added to an atom. So here this article gives information about difference between electronegativity and electron affinity to better understand this topic.

Definition of electronegativity:


The ability of atom to attract an electron from outside. This property is a qualitative property of an atom, and in order to compare the electronegativities of atoms in each element, a scale where relative electronegativity values reside is used.

Definition of electron affinity:


The amount of energy liberated when a molecule or neutral atom acquires an electron from outside. This electron addition causes the formation of a negatively charged by some of the chemical species.

Difference between electronegativity and electron affinity:


  • Electronegativity is of qualitative nature whereas electron affinity is quantitative in nature.
  • Electronegativity is a unitless quantity however is generally defined in term of pulling, the one who proposed the concept. However, electron affinity is measured in KJ/mol.
  • Electronegativity is higher when the element exhibits strong attracting ability, whereas electron affinity is higher when the nuclear charge is higher.
  • Fluorine is known to be the most electronegative element whereas chlorine is known to be an element with the highest electron affinity.
  • The value of electronegativity lies between 0.7 to 3.98. While electron affinity is said to be fixed because the electron releases almost similar energy whenever added to an atom.
  • Electronegativity applied in a single atom, while electron affinity applied either an atom or molecule.
  • The property by which an electron gets attracted to an atom is electronegativity. While the property that allows, release of energy when an electron is added to the atom is electron affinity.
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