The process of conversion of ` NH_(4) to NO_(2) to NO_(3)` is called

Options

A. Ammonification
B. Nitrification
C. `N_(2)` flxation
D. Denitrification

Answer

To answer the question regarding the process of conversion of `NH₄` (ammonium) to `NO₂` (nitrite) and then to `NO₃` (nitrate), we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Process**: The question asks about the conversion of ammonium to nitrite and then to nitrate. This process involves specific biochemical transformations carried out by certain bacteria.

2. **Identifying the Options**: The options provided include:
- A) Ammonification
- B) Nitrification
- C) Nitrogen fixation
- D) Denitrification

3. **Analyzing Each Option**:
- **Ammonification**: This is the process of converting organic nitrogen compounds into ammonia. It does not involve the conversion of ammonium to nitrite or nitrate.
- **Nitrification**: This is the correct process where ammonium (`NH₄`) is first converted into nitrite (`NO₂`) and then into nitrate (`NO₃`). This process is carried out by specific bacteria, such as Nitrosomonas (which converts ammonium to nitrite) and Nitrobacter (which converts nitrite to nitrate).
- **Nitrogen Fixation**: This process involves the conversion of atmospheric nitrogen (`N₂`) into ammonia (`NH₃`), not the conversion of ammonium to nitrate.
- **Denitrification**: This is the process of converting nitrates back into nitrogen gas, thus removing nitrogen from the soil.

4. **Conclusion**: Based on the analysis, the correct answer is **B) Nitrification**, as it specifically describes the conversion of ammonium to nitrite and then to nitrate.

### Final Answer:
The process of conversion of `NH₄` to `NO₂` to `NO₃` is called **Nitrification**.