Across
- 3. shafts dug deep into the ground to find and remove a mineral
- 4. deposits of moist sand and clay containing bitumen
- 5. energy that is nearly always available somewhere on earth's surface
- 6. the extraction of a mineral by removing a strip of the layers of soil and rock on top of the mineral deposit
- 9. energy made by the flow of an electric charge
- 10. process in which fuel burns because it combines rapidly with oxygen
- 11. an expression of how much of the energy put into a system actually does useful work
- 14. icelike solid that consists of molecules of methane within a crystal network of water molecules
- 15. energy an object has due to its position or shape
Down
- 1. occurs when sulfide minerals in exposed rock surfaces react with oxygen and rainwater to produce sulfuric acid
- 2. chemical compounds that are derived from oil and used to make products
- 4. rock filled with a mixture of hydrocarbons
- 7. a dark, liquid fossil fuel made mostly of hydrocarbons
- 8. cannot be replaced when completely used up
- 12. ability to do work or cause changer
- 13. energy an object has due to its motion