Across
- 5. The substance used up in a reaction
- 6. Gas which reacts with hydrogen to make water
- 7. A reaction which takes in energy
- 8. Particles must do this to react
Down
- 1. The substance made in a reaction
- 2. The energy needed to start a reaction
- 3. A reaction which releases energy
- 4. A form of energy released in many chemical reactions