How is electronegativity best defined?

Electronegativity is best defined as a measure of an atom's ability to attract electrons in a chemical bond. This property is essential in understanding how atoms interact with one another, particularly when forming molecules. When two atoms form a bond, the one with higher electronegativity will attract the shared electrons more strongly, leading to a polar bond if the atoms involved have different electronegativities.

The significance of electronegativity is evident in predicting the behavior of elements during chemical reactions, which affects the properties of the resulting compounds. For example, in a molecule like water (H₂O), oxygen is more electronegative than hydrogen, resulting in a partial negative charge on the oxygen and partial positive charges on the hydrogens. This arrangement of charges affects the physical properties of water, such as its high boiling point and solvent capabilities.

In contrast, other options describe different atomic characteristics. The atom's radius pertains to its size, while the quantity of electrons relates to its atomic number and does not necessarily provide insight into electron attraction. Ionization energy, which refers to the energy required to remove an electron from an atom, is related but distinctly different from electronegativity, as it focuses on the atom's tendency to lose electrons rather