The ionization enthalpy of molecular oxygen is identical to which of the following elements?

The correct answer relates to the similarity in ionization enthalpy values due to the electronic structure of molecular oxygen and xenon. Both oxygen and xenon are found in the second and fifth periods of the periodic table, respectively, though they are in different groups. Oxygen, being a group 16 element, has a notable tendency to gain or share electrons, while xenon, as a noble gas in group 18, is characterized by a complete valence shell, which impacts its ionization energy.

Xenon's relatively high ionization enthalpy stems from its stable electron configuration, making it energetically unfavorable to remove an electron, similar to what is observed for oxygen in its molecular form. While both species demonstrate significant ionization energies due to their stable configurations, the specific energies correspond more closely than those found in the other elements listed.

In contrast, nitrogen has a different electronic structure which leads to higher ionization enthalpy, and astatine has variable ionization characteristics due to being a halogen and less stable. Carbon, being a group 14 element, also exhibits different trends in ionization energy due to its lower nuclear charge compared to xenon. Thus, it is the electronic configuration and stability of xenon that makes its ion