Which of the following element(s) have only one non-zero oxidation state.

Options

A. `Be`
B. `O`
C. `F`
D. `N`

Answer

To determine which elements have only one non-zero oxidation state, we will analyze the oxidation states of the given elements: Beryllium, Oxygen, Nitrogen, and Fluorine.

### Step-by-Step Solution:

1. **Identify the elements**: The elements we need to analyze are Beryllium (Be), Oxygen (O), Nitrogen (N), and Fluorine (F).

2. **Analyze Beryllium (Be)**:
- Beryllium has the electronic configuration of 1s² 2s².
- It can lose its two outer electrons to achieve a noble gas configuration (similar to Neon).
- Therefore, Beryllium only shows a +2 oxidation state.
- **Conclusion**: Beryllium has only one non-zero oxidation state: +2.

3. **Analyze Oxygen (O)**:
- Oxygen has the electronic configuration of 1s² 2s² 2p⁴.
- It can exhibit multiple oxidation states:
- In OF₂, it has a +2 oxidation state.
- In O₂F₂, it can have a +1 oxidation state.
- In H₂O₂, it shows a -1 oxidation state.
- In H₂O, it shows a -2 oxidation state.
- **Conclusion**: Oxygen has multiple non-zero oxidation states (+2, +1, -1, -2).

4. **Analyze Nitrogen (N)**:
- Nitrogen has the electronic configuration of 1s² 2s² 2p³.
- It can show various oxidation states:
- In NO₂, it has a +4 oxidation state.
- In NH₃, it has a -3 oxidation state.
- **Conclusion**: Nitrogen has multiple non-zero oxidation states (+4, -3).

5. **Analyze Fluorine (F)**:
- Fluorine has the electronic configuration of 1s² 2s² 2p⁵.
- It can only gain one electron to achieve a stable noble gas configuration (Neon).
- Therefore, Fluorine only shows a -1 oxidation state.
- **Conclusion**: Fluorine has only one non-zero oxidation state: -1.

6. **Final Conclusion**:
- The elements that have only one non-zero oxidation state are:
- Beryllium (+2)
- Fluorine (-1)

### Summary:
- **Beryllium** has only one non-zero oxidation state: +2.
- **Fluorine** has only one non-zero oxidation state: -1.
- **Oxygen** and **Nitrogen** have multiple non-zero oxidation states.