Across
- 2. process in which one or more substances, the reactants, are converted to one or more different substances
- 4. the energy of chemical substances that is released when the substances undergo a chemical
- 10. proteins that help speed up metabolism, or the chemical reactions in our bodies.
- 12. a substance that is formed as the result of a chemical reaction
- 13. a process in which substances are changed into others
- 15. colourless, odourless gas that is stored in candles
- 16. the smallest unit that can live on its own and that makes up all living organisms and the tissues of the body
- 19. the invisible gaseous substance surrounding the earth, a mixture mainly of oxygen
- 20. light from the sun
Down
- 1. the surface or material on or from which an organism lives, grows, or obtains its nourishment.
- 3. the process by which plants use sunlight, water, and carbon dioxide to create oxygen and energy in the form of sugar.
- 5. the process of providing the energy that is required to initiate a combustion process
- 6. a usually reversible change in the physical properties of a substance,
- 7. This gas is combined with (see last question) to create a combustible reaction
- 8. is a substance that takes part in and undergoes change during a reaction.
- 9. this is a product in human cellular respiration
- 11. a change of materials into another, new materials with different properties and one or more than one new substances are formed
- 14. is a reaction of a substance with oxygen to give heat and light
- 17. a living organism of the kind exemplified by trees
- 18. an individual animal, plant, or single-celled life form.