Across
- 4. energy released is less than the energy required
- 6. one element replaces another in a compound
- 8. when complex compounds break down into simpler substances
- 9. material that increases rate of a reaction by lowering activation energy
- 11. material used to slow down the rate of reactions
- 14. energy released is greater than the energy required
- 15. matter cannot enter or escape to the surroundings
Down
- 1. substances that undergo the chemical change
- 2. solid that forms from two liquids during a chemical reaction
- 3. new substances that form
- 5. amount of a substance in a given volume
- 7. help control chemical reactions in the body at body temperature
- 10. minimum amount of energy needed to start a chemical reaction
- 12. when two or more elements combine to make a more complex compound
- 13. matter can enter or escape to the surroundings