Question

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

Explanation:

Group 18 nonmetals (noble gases) have full valence electron shells. This electron configuration makes them very stable and thus very nonreactive under normal conditions. In contrast, reactive elements (like Group 1 metals) have incomplete valence shells and readily gain, lose, or share electrons. Group 18 elements don't follow a "different pattern" or have "more exceptions" - their non - reactivity is a well - understood and consistent property due to their electron configuration.

Answer:

They are very nonreactive.