Natural resources

2. ____ is a solid fossil fuel that is mined from the bedrock.
7. nuclear power produces energy by splitting the nuclei of ____ atoms in a process called fission.
9. ____ is the most valuable gem stone.
11. _____ are natural resources like fossil fuels which supply is limited.
13. ______ are natural resources like wind and solar radiation that won't run out.
17. _____ have been formed when the remains of ancient organisms decomposed in anaerobic conditions under a layer of other materials in high pressure.
19. one way to make energy production more ______ is to use more renewable energy sources.

1. _____ are something found in nature that people use as raw materials, food or sources of energy.
3. many types of rock such as _____ is used in buildings.
4. in ______ energy is produced when wind rotates generators.
5. ____ is the most widely used material in building, and it's made out of cement.
6. = water power
8. aluminium and potassium are both _____ found in rocks.
10. ____ is refined from iron and it's the most common everyday metal.
12. ____ is the most important energy source in the world.
14. _____ is produced by burning organisms like plants.
15. harmful radiation caused by breaking down the unstable atom cores.
16. ____ is an example of a metal that is mined from the bedrock.
18. if a rock contains enough metal that it's worth extracting and refining, it is called ___.