What does electronegativity measure?

Electronegativity is defined as the tendency of an atom to attract a bonding pair of electrons. It essentially measures how strongly an atom can pull electron density towards itself when it is involved in a chemical bond with another atom. This characteristic plays a significant role in determining how electrons are distributed in molecules, influencing bond polarity and molecule behavior.

Atoms with high electronegativity, such as fluorine and oxygen, can create polar bonds when they are bonded to less electronegative atoms, leading to an unequal sharing of electron density. This phenomenon also explains various chemical properties, including solubility and reactivity, affecting how substances interact with one another in reactions.

Understanding this concept is vital for predicting the behavior of different elements and their compounds under various conditions in chemistry. The other options do not accurately capture the essence of electronegativity; instead, they relate to different properties of atoms, such as ionization energy or electron affinity, but do not specifically denote the ability to draw electron density towards itself.