What term refers to the degree of attraction an atom has for additional electrons?

The term that refers to the degree of attraction an atom has for additional electrons is electronegativity. This concept is integral to understanding how atoms interact with each other, especially in chemical bonding. Electronegativity quantifies an atom's ability to attract and hold onto electrons when forming compounds.

For example, in a covalent bond where two atoms share electrons, the atom with higher electronegativity will attract the shared electrons more strongly, resulting in a polar bond. This property is essential in predicting how atoms will behave in chemical reactions, influencing the formation of bonds and the properties of molecules.

Other terms, such as ionization energy and electron affinity, relate to different aspects of atomic behavior. Ionization energy concerns the energy required to remove an electron from an atom, while electron affinity measures the energy change when an electron is added to a neutral atom. Atomic radius refers to the size of the atom itself, rather than its ability to attract electrons. Thus, electronegativity is specifically focused on the attraction of electrons, making it the correct choice.