Across
- 4. the cells in your body that contain thousands of biological catalysts
- 10. a way to show a chemical reaction using symbols
- 12. matter can enter or escape from its surroundings
- 13. the minimum amount of energy needed to start a chemical reaction
- 14. when matter during a chemical reaction matter is not created or destroyed
- 16. the new substances that form from a chemical change
- 18. when two elements in compounds swap places
- 20. when two or more elements or compounds combine to make a more complex substance
Down
- 1. any change that alters the form or appearance of any substance but does not change it into another substance
- 2. a change in matter that produces one or more substances
- 3. a number placed in front in a chemical formula in an equation
- 5. a material used to decrease the rate of a chemical reaction
- 6. matter cannot leave or enter
- 7. the substance that undergoes the chemical changes
- 8. a reaction that absorbs heat and feels cold
- 9. when a complex substance breaks down into simpler products
- 11. the amount of a substance in a given volume
- 15. increases the rate by lowering the activation energy needed
- 17. a solid that forms from liquids during a chemical reaction
- 19. a reaction that releases heat and feels hot