Answer:
Xenon’s relatively low ionization energy
Explanation:
Ionization energy is the minimum amount of energy that is necessary to remove or dislodge the most loosely bound electron called the valence electron. When this happens and the valence electrons are removed they then go to the other atom and vice versa and bonding occurs.
Since Xenon is unreactive then its relatively low ionization energy is responsible for its bonding with fluorine.