The scientist recorded the subjects' reactions after administering the new drug.

The reactional swelling after the vaccine was minor and subsided within two days.

The party's shift toward reactionism alarmed moderates, who feared a rollback of civil liberties.

Her immediate reaction to the news was to call her family.

Advanced students often study rearrangement reactions to understand how molecular frameworks change during synthesis.

In the lab, we observed several chemical reactions that produced unexpected color changes.

Biochemists often study redox reactions to understand cellular respiration and energy transfer.

Scientists study nuclear reactions to understand energy production in stars.

The new policy received mixed reactions from employees and management alike.

Small policy shifts can trigger chain reactions across the global economy.