What does electronegativity refer to in atomic interactions?

Electronegativity refers to the tendency of an atom to attract shared electrons in a chemical bond. This characteristic plays a vital role in determining how atoms interact with one another, particularly when forming covalent bonds. Atoms with high electronegativity have a stronger pull on the electrons they share with other atoms, leading to uneven distribution of electronic charge, which can create polar bonds.

Understanding electronegativity is essential because it influences molecular behavior, reactivity, and properties such as polarity and solubility. For instance, in water (H2O), the electronegativity difference between oxygen and hydrogen atoms leads to a polar molecule, affecting how it interacts with other substances.

In contrast, other choices touch on unrelated atomic properties. The mass of an atom, the number of protons, and size comparisons between atoms do not define how atoms interact when sharing electrons in chemical bonds.