Ammonification: process by which bacteria break the bonds in the nitrogen gas, and combine the free nitrogen atoms with hydrogen to form ammonium

Biogeochemical Cycles: describe the movement of matter across the surface of the planet, from the geosphere to the atmosphere to the biosphere to the hydrosphere and back again

Denitrification: the process of converting nitrites, nitrates, and ammonium back into N2 gas

Nitrification: process by which electricity, in the form of lightning, breaks the strong bond between the N₂ molecule, enabling free nitrogen atoms to bond with oxygen in the air to form ammonia, nitrites and nitrates

Nitrogen Cycle: biogeochemical cycle that circulates the nutrient nitrogen through Earth's spheres

Nitrogen Fixation: process of converting nitrogen into a form usable by organisms

Nutrient Pollution: addition of too much nitrogen, typically due to the addition of fertilizers

Phosphorous Cycle: biogeochemical cycle that circulates the nutrient phosphorous through Earth's spheres

Rhizobium: colonies of bacteria that perform nitrification and ammonification