Lorenzo is making a prediction. "i learned that nonmetals
increase in reactivity when moving from left to right. so i
predict that xenon will be more reactive than iodine." is
lorenzo correct? if so, why? if not, explain his error.

Lorenzo is not correct because xenon is a noble gas which is nonreactive or inert.

Explanation:

The reactivity of nonmetals  increases when moving from left to right in the periodic table. They have a high attraction for electrons and tend to gain electrons. The most reactive nonmetal element is fluorine. Noble gases are the least reactive because they have the most stable arrangement of electrons (eight valence electrons). So they rarely react with other elements. So the prediction that xenon will be more reactive than iodine is incorrect.