biogeochemical

3. a biogeochemical cycle that involves the continuous movement of water on, above and below the surface of the Earth. The mass of water on Earth remains fairly constant over time
4. It is colorless, odorless, non-toxic, and highly combustible. Constituting about 75% of all normal matter, hydrogen is the most abundant chemical element in the universe.
6. any body of water above ground, including streams, rivers, lakes, wetlands, reservoirs, and creeks.
8. a mineral that makes up 1% of a person's total body weight.
13. the process of water movement through a plant and its evaporation from aerial parts, such as leaves, stems and flowers
15. a microbial process by which reduced nitrogen compounds (primarily ammonia) are sequentially oxidized to nitrite and nitrate
16. a chemical element; it has symbol N and atomic number 7.
17. colourless, odourless, tasteless gas essential to living organisms

1. the loss or removal of nitrogen or nitrogen compounds
2. nature's way of reusing carbon atoms, which travel from the atmosphere into organisms in the Earth and then back into the atmosphere over and over again.
5. conversion of a substance from the solid to the gaseous state without its becoming liquid
7. water that exists underground in saturated zones beneath the land surface
9. happens when a liquid turns into a gas
10. water which collects as droplets on a cold surface when humid air is in contact with it
11. nonmetallic chemical element in Group 14 (IVa) of the periodic table
12. the biogeochemical cycle by which nitrogen is converted into multiple chemical forms as it circulates among atmospheric, terrestrial, and marine ecosystems
14. drizzle, rain, sleet, snow, ice pellets, graupel and hail