Final answer:
Fluorine (Element Z) has a greater first ionization energy than sodium (Element X) because of its higher effective nuclear charge and proximity to a noble gas electron configuration.
Step-by-step explanation:
The first ionization energy (IE) is the energy required to remove the most loosely bound electron from a neutral atom in its gaseous state. According to the provided configurations, Element X has an electron configuration of 1s22s22p63s1, which is the electron configuration for sodium (Na), and Element Z has an electron configuration of 1s22s22p5, which represents fluorine (F). Fluorine (Element Z) would have a greater first ionization energy than sodium (Element X) due to its higher effective nuclear charge and greater electron affinity. As we move across a period in the periodic table, the ionization energy generally increases because atomic size decreases, and the electrostatic interactions between the nucleus and valence electrons increase. This makes electrons harder to remove, especially when approaching noble gas configurations like that of fluorine.