Combustion

7. Fuels: Fuels formed from the remains of ancient plants and animals, such as coal, oil, and gas.
10. Machines that convert energy from combustion into mechanical motion.
11. The process where a liquid forms solid crystals, often by cooling or evaporating.
12. A small flash of light or heat that can start combustion.
13. A rapid and violent release of energy caused by combustion or other reactions.
14. Fuels made from living organisms or their waste, like ethanol or biodiesel.
17. Fuels: Fuels made from resources that can be replenished, like biofuels.
19. Pop Sound: The noise made when hydrogen gas burns quickly in the presence of a flame.
21. A chemical reaction where a substance reacts with oxygen, releasing energy as heat and light.
22. A reaction where a substance combines with oxygen, often releasing energy.

1. Reacting with great energy or intensity, like a fire burning strongly.
2. A historical, now-discredited theory that substances released a material called "phlogiston" during burning.
3. Fuels: Fuels from finite resources, like coal or oil, which cannot be replaced once used.
4. Energy released from reactions involving atomic nuclei, such as in nuclear power plants.
5. A compound made of hydrogen and carbon atoms, such as methane or petrol.
6. The visible, glowing part of a fire caused by combustion.
8. The environment around a reaction, including air, temperature, and materials nearby.
9. Harmful substances released into the environment, often as a by-product of combustion.
15. A compound formed when an element reacts with oxygen, such as carbon dioxide.
16. of Conservation of Mass: The principle stating that mass cannot be created or destroyed in a chemical reaction.
18. Decomposition: A reaction where heat causes a substance to break down into simpler substances.
20. A reaction that releases heat to the surroundings.