| Term | Definition |
| Macronutrients | Elements requried in large amounts vital for living things, the "big 6" are: Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorous, Sulfur |
| Micronutrients | Elements required in small amounts but still vital for living things |
| Residence Times | Average length of time an element is stored in a certain resevior before transferring to the next |
| Flux/Rate of Transfer | Amount of an element that leaves/enters a resevoir per unit of time |
| Limiting Factor | Amount of an element that leaves/enters a resevoir per unit of time |
| Respiration | The process when animals or plants exhale water in a gas form |
| Percolation | Water transferring back to the soil from plants or dead animals |
| Transpiration | Plants releasing water back into the atmosphere |
| Photosynthesis | The process where plants take in sunlight and transform it into glucose to make energy themselves |
| Assimilation/Biosynthesis | The process to make carbohydrates or DNA |
| Coalification | The process when heat and pressure break down fossils to create fossil fuels |
| Combustion | The burning of fossil fuels to create CO2 |
| Eutrophication | When fertilizers get into bodies of water, creates algae blooms and the decompostion sucks all the O2 |
| Nitrogen Fixation | When atmospheric N2 is nitrate or ammonia by lightening strikes or bacteria |
| De-Nitrification | Bacteria in soil/water "strip" oxygen off NO3 and convert it back to N2 |
| Leaching | When elements percolate through the soil |
| Ammonification | When elements percolate through the soil |
| Nitrification | toxic ammonia is converted by bacteria to non toxic nitrate and nitrite |
| Igneous Rock | Formed by volcanic eruption lava/magma flows |
| Sedimentary Rock | Formed from lithification by weathering/erosion that has a layered appearence |
| Metamorphic Rock | Rock formed in extreme heat and pressure |