Natural resourses

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Across
  1. 3. less visibility
  2. 6. situation in which something needed cannot be obtained in sufficient amounts.
  3. 10. a compound of nitrogen and hydrogen
  4. 12. a group of atoms bonded together
  5. 13. loosely used term for molecules present in organisms
  6. 14. form of dissolved nitrogen that occurs naturally in the water column
  7. 15. region occupied by living organisms
  8. 17. abnormal condition that negatively affects the structure or function of all or part of an organism
  9. 19. the rigid outer part of the earth
  10. 20. fog and smoke
  11. 21. air is mostly filled with
  12. 22. for breathing
Down
  1. 1. process of rotting
  2. 2. breathing
  3. 3. the action or process of fixing
  4. 4. plants convert light energy into chemical energy
  5. 5. inorganic compounds made up of nitrogen and oxygen
  6. 7. It is both a natural and a man-made product that occurs in the Earth's upper atmosphere (the stratosphere) and lower atmosphere (the troposphere).
  7. 8. introduction into the environment of a
  8. 9. useful or useless things thrown away
  9. 11. chemical used to kill pests
  10. 16. removes the nitrates or nitrites from (soil, air, or water) by chemical reduction.
  11. 18. the process of burning something.
  12. 20. the gaseous products of burning materials