Questions: In which cycle does the atmosphere play virtually no role? a.) nitrogen b.) oxygen c.) hydrological d) phosphorus

Solution Steps

To determine which cycle involves the atmosphere the least, we need to briefly understand the role of the atmosphere in each of the given cycles:

• Nitrogen Cycle: The atmosphere plays a significant role as it is composed of approximately 78% nitrogen gas (N₂). Nitrogen fixation, a key process in the nitrogen cycle, involves converting atmospheric nitrogen into forms usable by living organisms.

• Oxygen Cycle: The atmosphere is crucial in the oxygen cycle as it contains about 21% oxygen. Processes like photosynthesis and respiration involve the exchange of oxygen between the atmosphere and living organisms.

• Hydrological Cycle: The atmosphere is integral to the hydrological cycle (water cycle) as it involves the evaporation of water into the atmosphere, condensation to form clouds, and precipitation back to the Earth's surface.

• Phosphorus Cycle: The phosphorus cycle is unique because it does not include a gaseous phase under normal conditions. Phosphorus is typically found in rocks, soil, and sediments and cycles through water, soil, and living organisms without involving the atmosphere.

From the analysis above, the phosphorus cycle is the only cycle where the atmosphere plays virtually no role. It primarily involves the movement of phosphorus through the lithosphere, hydrosphere, and biosphere.

Final Answer