Term wet deposition and dry deposition is generally used for :

Options

A. Deposition of soil
B. Deposition of organic matter in lake
C. `CO_(2)` accumulation (green house effect)
D. Acid rain

Answer

**Step-by-Step Solution:**

1. **Understanding the Terms:**
- The terms "wet deposition" and "dry deposition" are primarily associated with the phenomenon of acid deposition in the environment.

2. **Defining Wet Deposition:**
- Wet deposition refers to the process where acidic compounds are mixed with water or water vapor. This can occur when pollutants like sulfur dioxide and nitrogen oxides combine with moisture in the atmosphere.

3. **Mechanism of Wet Deposition:**
- Wet deposition occurs when this contaminated moisture falls to the ground in various forms, such as rain, snow, fog, or hail. This process contributes to what is commonly known as acid rain.

4. **Defining Dry Deposition:**
- Dry deposition, on the other hand, involves the accumulation of acidic substances in the form of dust or gases. These pollutants settle on surfaces without the involvement of precipitation.

5. **Mechanism of Dry Deposition:**
- In dry deposition, when normal rain occurs, it can wash away these accumulated acids from surfaces (like plants and buildings) and mix them with rainwater, resulting in acidic runoff.

6. **Impact of Acid Deposition:**
- Both wet and dry deposition lead to the formation of acid rain, which has a pH of about 4.2 to 4.4. This acidic rain can be harmful to wildlife, plants, and the overall environment.

7. **Conclusion:**
- Therefore, the terms wet deposition and dry deposition are specifically used to describe the processes through which acid deposition occurs, ultimately leading to acid rain.

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