Across
- 2. a substance that speeds up a chemical reaction, or lowers the temperature or pressure needed to start one, without itself being consumed during the reaction
- 5. the starting materials in a chemical reaction
- 7. a process in which one or more reactants are converted to one or more different substances
- 10. a chemical reaction that produces heat (it feels hot to touch)
- 11. the burning of a fuel, where it reacts with oxygen to create heat and light
- 12. the physical breakdown of large pieces of food into smaller pieces (eg. chewing)
- 13. a substance with a pH greater than 7
- 15. a change when no new substance is formed
- 16. a substance with a pH less than 7
- 18. a chemical reaction that absorbs thermal energy from its surroundings (it feels cold to touch)
- 19. the amount of a substance in a defined space
- 20. another name for an upset stomach
- 21. a form of energy (thermal)
Down
- 1. a substance with a pH of 7
- 3. a base which neutralises excess acid in the stomach
- 4. using acids and enzymes to break down the food into simpler nutrients that can be absorbed and used by the body cells
- 6. the process by which food, in the form of sugar (glucose), is transformed into energy within cells
- 8. a substance that is formed as the result of a chemical reaction
- 9. the measure of how much exposed area a solid object has
- 14. a change when a new substance is formed
- 17. the speed at which a chemical reaction takes place