Which periodic property reflects the capacity of an atom to attract electrons in a bond?

The correct answer is electronegativity, which is the property that measures an atom's ability to attract and hold onto electrons when it forms a chemical bond. In a covalent bond, for example, electronegativity differences between the atoms involved determine how electron density is shared or transferred, influencing whether the bond is polar or nonpolar.

Electronegativity is crucial for understanding the behavior of atoms in a compound as it impacts molecular geometry, bond polarity, and reactivity. Higher electronegativity values indicate a stronger attraction for electrons, while lower values suggest a weaker attraction.

In contrast, atomic radius, ionization energy, and electron affinity refer to different atomic properties. Atomic radius deals with the size of the atom, which affects bond lengths but does not directly reflect the atom's ability to attract electrons. Ionization energy refers to the energy required to remove an electron, indicating how tightly an atom holds onto its electrons rather than how it attracts additional electrons. Electron affinity is related to the change in energy when an atom gains an electron, but it does not encompass the broader concept of attraction in bonds between two atoms. Thus, electronegativity specifically captures the capacity to attract electrons in bonding settings.