Nitrogen cycle

Name: ______________________   Date: ____________

Use the clues to fill in the crossword.

Across

  1. 5. Impregnation with ___ or a compound of ___ (14)
  2. 7. The substance of a living cell (10)
  3. 8. Any compound containing the ___ group (plural) (8)
  4. 9. Abrupt electric discharge from cloud to cloud or from cloud to earth accompanied by the emission (9)

Down

  1. 1. An erect or climbing bean or pea plant of the family ___ (plural) (7)
  2. 2. A pungent gas compounded of nitrogen and hydrogen (7)
  3. 3. The chemical process in which a nitro group is added to an organic compound (13)
  4. 4. Layer of air around the Earth (10)
  5. 6. The radical -NO2 or any compound containing it (plural) (8)