Energy

3. energy from the sun
4. a dangerous condition in which fuel rods inside a nuclear reactor melt
6. the process of burning a fuel
7. a factory in which crude oil is heated and separated into fuels and other products
9. the percentage of energy that is used to do work
11. the practice of reducing energy use
13. the splitting of an atom's nucleus into two smaller nuclei and neutrons
15. a substance that provides energy as a result of a chemical change

1. electricity produced using the energy of flowing water
2. material that blocks heat transfer between the air inside and outside the building
5. the central core of an atom that contains the protons and neutrons
8. a change from one form of energy to another
10. a cadmium rod used in a nuclear reactor to absorb neutrons from fission reactions
12. oil;liquid fossil fuel
14. an energy rich substance formed from the remains of organisms