Across
- 3. Needed to break bonds
- 6. absorbes heat
- 10. When two or more elements mix together
Down
- 1. A source of energy
- 2. a substance that takes part in and undergoes change during a reaction
- 4. Joined by a chemical reaction
- 5. A process in which a chemical substance changes because of the addition of oxygen
- 7. releases heat
- 8. Substance reacts with oxygen and gives off heat
- 9. To separate