react

Everyday

1. To act, speak or feel in a certain way because of something that has happened (How did she react to the news?). tree →
2. (science) To change when mixed with another substance, making something new (chemical reaction). tree →
3. (health) To become ill or get a rash after eating, touching or breathing something (an allergic reaction). tree →
4. React against: to do the opposite of what you are told or what others do. tree →

In the lessons

In science, when vinegar and baking soda react they make carbon dioxide gas (fizzing); iron reacts with water and air to make rust. In feelings lessons, we learn to react calmly — stop, breathe, think — rather than lashing out. In health: some people react badly to peanuts or bee stings, and need help fast. In sport and safety, quick reactions help you dodge a ball or stop your bike. Phrases: react to, react with, react quickly, overreact, allergic reaction.

Examples

• How did your mum react when you told her? tree →
• Vinegar reacts with baking soda and fizzes. tree →
• He reacted quickly and caught the falling glass. tree →
• Some people react to peanuts and need medicine fast. tree →
• Don't react angrily — count to ten first. tree →
• Iron reacts with water and air to make rust. tree →
• The cat reacted to the noise by hiding under the bed. tree →

Note

«React to» something (a person reacts to news); «react with» something (a chemical reacts with another). Noun: reaction. «Overreact» = react too strongly.