Question

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 is incorrect. Because xenon is a noble gas, and the iodine is a halogen. The halogens are more reactive than noble gases. Xenon is least reactive Lorenzo can also look at the electrons in the shell when making his predictions.

Explanation: Answer these when making your own response to the answer:

1. nonmetals on the right need to gain fewer electrons to form an ion, so they are more reactive.

2. The noble gases already have a full outer shell.

3. The noble gases break the trend by being less reactive than the elements to their left.

Test sample response:

Sample Response: Lorenzo is not correct. Nonmetals increase in reactivity from left to right because nonmetals on the right have more valence electrons. They need to gain fewer electrons to have a full outer shell. However, this trend only continues until group 17, because the noble gases already have a full outer shell. Therefore, their reactivity is the least of all the elements.

Answer 2

Lorenzo is incorrect. Xenon is a noble gas, and iodine is a halogen. Halogens are way more reactive than noble gases (and xenon is one of the least reactive of those). You also have to pay attention to the families and the number of electrons in the valence shell when making these predictions.