Combustion and chemical reactions

4. A gas produced during combustion, consisting of carbon and oxygen.
7. A substance that speeds up a chemical reaction without being consumed itself.
8. A chemical reaction where a substance gains electrons.
10. The process of initiating combustion.
12. A chemical equation where the number of atoms of each element is the same on both sides.
14. A substance that undergoes change in a chemical reaction.
15. A process that rearranges the molecular structure of substances to form new substances.
17. The process of burning something.
18. A chemical reaction that absorbs heat energy.
19. A substance that is formed as a result of a chemical reaction.
20. A chemical element essential for combustion to occur.

1. The visible, gaseous part of a fire.
2. A chemical reaction where a substance loses electrons, usually to oxygen.
3. A compound consisting of hydrogen and carbon atoms, often used as fuel.
5. A material that can be burned to release energy.
6. A chemical reaction where iron reacts with oxygen and water to form rust (iron oxide).
9. A symbolic representation of a chemical reaction.
11. Energy associated with the motion of particles in a substance.
13. The minimum energy required to start a chemical reaction.
16. A chemical reaction that releases heat energy.