Q9.55P - Chemistry: Molecular Nature Of Matter And Change

Question

How does electronegativity differ from electron affinity?   

Step-by-Step Solution

Answer

Electronegativity is the property of the atom to attract the electron of an atom whereas electron affinity is defined as the energy liberated when a molecule or atom acquires an electron from another atom or molecule.

Step 1: Definition

• Electronegativity is defined as the property of an atom/molecule to attract the electron of the other atom/molecule. Every atom has an electronegativity property which depends on the size of the atom and also the electron cloud. Electronegativity is inversely proportional to the size of the atom.
• Electron-affinity is defined as the energy liberated by an atom/molecule when the electron is gained from another atom/molecule. 

Step 2: Explanation

There is a distinct difference between electronegativity and electron affinity.

Electronegativity is a qualitative property which depends on the electron cloud and size of the atom. It is applied to a single atom.

For example, Fluorine is the most electronegative atom.

 

Electron affinity is a quantitative property which depends on the valence shell of the atom. It is the amount of energy liberated when the electron is gained by the atom/molecule and the electron is increased in the valence shell. The unit of the electron affinity or energy is eV or Joule.

For example, when chlorine gains electrons in its valence shell, it releases some energy.