DarbySmith

2. Single-celled organisims that live in water. They are an important store of carbon or carbon sink.
5. Hydrated iron (III) oxide.
7. A base that dissolves in water.
9. A green chemical found in the chloroplasts of green plants.
12. A reaction of an acid with a base, forming a salt and water.
14. Simple written description of what is happening in a reaction.
15. A substance that releases hydroxide ions.
16. Highly combustible chemicals; petrol is a mixture of this.
19. A biological catalyst that speeds up a reaction.
20. A way of protecting aluminium from corrsion, by deliberately creating a layer of aluminium oxides over it.

1. A black coating of silver sulfide that is produced when silver reacts with sulfur in the atmosphere; chemical formula Ag2S.
3. A simple sugar formed by photosynthesis and used in respiration.
4. Chemicals produced in a chemical reaction. They are written on the right-hand side of the arrow.
6. A process in which chemicals move, caused by different concentrations of the chemical.
8. A scale used to measure the concentration of hydrogen ions in a solution.
10. Endothermic reaction that takes place in green plants. Uses energy from sunlight to combine water and carbon dioxide and produce glucose and oxygen gas.
11. A chemical reaction that releases energy.
13. A substance that releases hydrogen ions into an aqueous solution.
17. A term used to describe materials that store carbon in their structures. Plants and animals can be thought of as carbon sinks.
18. Rain that has acids such as nitric acid and sulfuric acid dissolved in it.