Across
- 3. the percentage of energy that is actually used to perform work
- 6. used to slow down the chain reactions
- 8. can only be used when sun is shining
- 11. lightbulbs that use less energy
- 12. a substance that provides energy such as heat, light, motion, or electricity
- 14. oil is mainly used for
- 20. are compounds that are made from oil
- 22. are the chemical compounds which fossil fuels are made of
- 23. reducing energy use
- 24. lightbulbs that use more enegy
- 25. the least used of the three fossil fuels for electricity production
- 26. form of power produced by flowing water
- 29. resources that can run out, but can be formed again after millions of years
Down
- 1. percentage of coal mined in the U.S.A exported to other countries
- 2. adding the alcohol to gasoline forms a mixture
- 4. two hydrogen nuclei combine to create a helium nucleus
- 5. form of a fuel and examples are wood and plant parts
- 7. a layer of material that traps air to help block the transfer of heat
- 9. the neutron hits the U235 nucleus, and the nucleus splits into two smaller nuclei and two more neutrons
- 10. most of coal is used for
- 13. a fossil fuel used a majority of the time back then
- 15. thermal energy converted to mechanical energy
- 16. form of energy and is heat from earth's interior
- 17. the original source of energy in wind and flowing water
- 18. where uranium fuel undergoes nuclear fission
- 19. resources that can be used repeatedly
- 21. are coal, natural gas, and petroleum
- 27. when the fuel rods melt, it is also known as
- 28. a factory in which crude oil is heated and separated into fuels and other products