In which of the following biogeochemical cycles is at mospheric phase absent/negligible?

Options

A. Nitrogen
B. Sulfur
C. Phosphorus
D. Water

Answer

To solve the question "In which of the following biogeochemical cycles is the atmospheric phase absent/negligible?", we can follow these steps:

### Step 1: Understand the Biogeochemical Cycles
Familiarize yourself with the four biogeochemical cycles mentioned: nitrogen, sulfur, phosphorus, and water. Each cycle has different phases, including atmospheric, terrestrial, and aquatic phases.

### Step 2: Analyze Each Cycle
- **Nitrogen Cycle**: This cycle includes an atmospheric phase where nitrogen gas (N2) is present in the atmosphere and is fixed into usable forms by certain bacteria.
- **Sulfur Cycle**: This cycle also has an atmospheric phase where sulfur gases, such as sulfur dioxide (SO2), are present in the atmosphere.
- **Water Cycle**: The water cycle includes an atmospheric phase where water vapor is present in the atmosphere, leading to precipitation.
- **Phosphorus Cycle**: This cycle primarily occurs in sedimentary form. Phosphorus does not have a significant gaseous phase in the atmosphere. It is mainly found in rocks, soils, and living organisms.

### Step 3: Identify the Cycle Without an Atmospheric Phase
From the analysis, it is clear that the phosphorus cycle is the only one that does not have a significant atmospheric phase. It operates mainly through the weathering of rocks and the recycling of phosphorus in soil and living organisms.

### Conclusion
The correct answer to the question is **phosphorus cycle**, as it is the only cycle among the options where the atmospheric phase is absent or negligible.

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