Name the process in which nitrogen in Earth's atmosphere converted into ammonia.

Options

A. Pasteurization
B. Assimilation
C. Nitrogen fixation
D. Nitrogen cycle

Explanation

**Step-by-Step Solution:**

1. **Understanding the Question:** The question asks for the process by which nitrogen in the Earth's atmosphere is converted into ammonia.

2. **Identifying Relevant Processes:**
- The options provided include:
- Pasteurization
- Assimilation
- Nitrogen fixation
- Nitrogen cycle

3. **Analyzing Each Option:**
- **Pasteurization:** This process involves heating liquids to kill microbes. It does not relate to nitrogen conversion.
- **Assimilation:** This refers to the absorption of nutrients by organisms, not the conversion of nitrogen.
- **Nitrogen Fixation:** This is the process where nitrogen gas (N₂) from the atmosphere is converted into ammonia (NH₃) by certain bacteria in the soil.
- **Nitrogen Cycle:** This describes the movement of nitrogen through the environment but does not specifically refer to the conversion process.

4. **Selecting the Correct Answer:** Based on the analysis, the correct process that converts nitrogen in the atmosphere into ammonia is **Nitrogen fixation**.

5. **Final Answer:** The process in which nitrogen in Earth's atmosphere is converted into ammonia is called **Nitrogen fixation**.

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