Across
- 4. mass cannot be created of destroyed
- 7. a substance that is formed in a chemical reaction
- 9. speeds up a chemical reaction
- 10. when heat is released
- 11. makes a new substance with new properties
Down
- 1. a process in which one or more substances are transformed into others
- 2. slows down a chemical reaction
- 3. are the biological substances that act as catalysts and help complex reactions occur everywhere in life
- 5. a symbolic representation of a chemical reaction
- 6. when heat is absorbed
- 8. a substance that takes part in a chemical reaction