Chapter 3 Natural Resources

12345678910111213141516171819
Across
  1. 3. repeating with small improvements
  2. 7. certain heavy metals that react easily with other elements
  3. 8. the process of returning the land to its former environmental condition
  4. 10. the reduction of one desirable characteristic in order to increase another
  5. 14. the conversion of kinetic energy in water to electric energy
  6. 15. combustable material stored in fossilized organisms
  7. 17. the way engineers identify and solve problems
  8. 18. a natural material made up of one or more minerals
  9. 19. use of a resource in amounts that do not exceed its production
Down
  1. 1. a limit or restriction on the solution
  2. 2. a sedimentary rock that contains kerogen, a solid bituminous material
  3. 4. a limited amount of the resource exists
  4. 5. contain bitumen, a thick, sticky substance that does not flow like petroleum
  5. 6. the recovery of useful material from waste
  6. 9. the resource can be replaced at the rate it is made
  7. 11. the required or desired properties of a solution
  8. 12. the conversion of heat energy from the Earth's interior to electric energy
  9. 13. mixtures of metals
  10. 16. the process by which materials are pumped underground to break up rock and release oil or natural gas