Which statement best defines electronegativity?

• A. The energy required to remove an electron
• B. The distance between the nucleus and electrons
• C. The attractive force that an atomic nucleus exerts on shared electrons
• D. The mass of the atom

Answer: (C)

Electronegativity is the tendency of an atom to attract electrons toward itself in a covalent bond. In a bond, electrons are shared, but the pull on those shared electrons isn’t the same for every atom. An atom with a stronger pull from its nucleus draws more electron density toward itself, making the bond more polarized. This pull depends on factors like the effective nuclear charge and the size of the atom—smaller atoms with a higher nuclear charge grab electrons more strongly, which is why fluorine and oxygen rank highly in electronegativity, while metals with lower pull are less electronegative. The option described as the attractive force the nucleus exerts on shared electrons best captures this concept. Other descriptions refer to different properties: energy needed to remove an electron is ionization energy, the distance between the nucleus and electrons describes atomic size, and mass is simply atomic mass.