Across
- 2. the most common energy source on earth are ______ fuels
- 5. fossil fuels release ________ into the atmosphere
- 6. _______ is a dark, carbon rich fossil fuel
- 7. _________ is an accumulation of partially decayed vegetation or organic matter.
- 8. the process of burning fuel to produce
- 9. a method of extracting oil and gas by fracturing rock layers
- 12. many oil reserves are found in the _______ east
- 15. natural gas consists of mostly ________ and other hydrocarbons
- 16. ________ is formed from the decomp. of organic materials underground
- 17. _______ fuels are created from the remains of living organisms
- 18. uranium is a _______ element used in nuclear power plants to generate electricity
- 19. ________ has the highest carbon content of any type of coal
- 21. coal is formed from the fossilized remains of _______ and animals
Down
- 1. non-renewable resources take millions of years to form are _________
- 3. natural gas is often used for ________ homes
- 4. dioxide __________ is a byproduct of burning fossil fuels
- 10. the burning of fossil fuels is a major reason for _______ change
- 11. oil is a liquid fossil fuel also known as _______
- 13. _________ horizon can be caused by oil spills in the ocean
- 14. the thick, sticky form of crude oil found in tar sands
- 20. fossil fuels are formed under intense ________ and pressure