Combustion

2. the process of adding oxygen to something
5. the process of a substance or chemical element oxidizing
10. Rapid oxidation producing heat and light
11. a stream of hot, burning gas from something on fire
13. any basic substance that is used in or produced by a reaction involving changes to atoms or molecules
15. the process of burning something completely
16. The process of burning
18. If a substance oxidizes, it combines with oxygen and loses hydrogen to form another substance, and if something oxidizes a substance, it causes it to do this.
19. the power and ability to be physically and mentally active

1. a chemical combination of hydrogen and carbon, such as in oil or petrol
3. the electrical system in an engine that causes the fuel to burn or explode in order to start the engine
4. the fact of something such as a bomb exploding
6. a substance that is used to provide heat or power, usually by being burned
7. the part of a cooker, light, etc. that produces flame or heat
8. the force you produce when you press something
9. the process of a substance or chemical element oxidizing
12. an occasion when two or more substances react with and change each other
14. small dry sticks or other materials used to start a fire
17. a chemical element that is a gas with no smell or colour. Oxygen forms a large part of the air on earth, and is needed by animals and plants to live.