Question

which feature is unique to group 18 nonmetals? (1 point)
○ they follow a different pattern of reactivity.
○ they are very reactive.
○ they are very nonreactive.
○ they have more exceptions to reactivity rules.

Explanation:

Group 18 nonmetals (noble gases) have a full valence electron shell, making them very nonreactive (inert) under normal conditions. The other options are incorrect: they don't follow a different reactivity pattern in a unique way, they are not very reactive, and they don't have more exceptions to reactivity rules.

Answer:

C. They are very nonreactive.