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.

Answer 1

Lorenzo's prediction is incorrect. The reactivity of nonmetals does not follow a straightforward trend of increasing reactivity from left to right across the periodic table. In fact, for nonmetals, reactivity generally increases from top to bottom within a group (column) and decreases from left to right across a period (row).

In the case of iodine (I) and xenon (Xe), iodine is a halogen located in group 17 and has a higher reactivity than xenon, which is a noble gas located in group 18. Noble gases are characterized by their full valence electron shells, making them largely inert and unreactive under normal conditions. Therefore, xenon is less reactive than iodine.

Lorenzo's misunderstanding lies in the application of the trend of reactivity for nonmetals. He incorrectly assumes that nonmetals in general become more reactive from left to right without considering the specific group properties of the elements involved.