Which of the following is superoxide ?

Options

A. `Na_(2)O_(2)`
B. `BaO_(2)`
C. `CsO_(2)`
D. `MnO_(2)`

Explanation

To determine which of the given compounds is a superoxide, we will analyze each option step by step.

### Step 1: Identify the compounds
The given compounds are:
1. Na₂O₂ (Sodium peroxide)
2. BaO₂ (Barium peroxide)
3. CsO₂ (Cesium superoxide)
4. MnO₂ (Manganese dioxide)

### Step 2: Understand the definitions
- **Oxide Ion (O²⁻)**: Contains one oxygen atom with a -2 charge.
- **Peroxide Ion (O₂²⁻)**: Contains two oxygen atoms with a -2 charge, represented as O-O²⁻.
- **Superoxide Ion (O₂⁻)**: Contains two oxygen atoms with a -1 charge, represented as O₂⁻.

### Step 3: Analyze each compound
1. **Na₂O₂ (Sodium peroxide)**:
- Contains the peroxide ion (O₂²⁻).
- Therefore, it is not a superoxide.

2. **BaO₂ (Barium peroxide)**:
- Also contains the peroxide ion (O₂²⁻).
- Therefore, it is not a superoxide.

3. **CsO₂ (Cesium superoxide)**:
- Contains the superoxide ion (O₂⁻).
- This is a superoxide.

4. **MnO₂ (Manganese dioxide)**:
- Contains oxide ions (O²⁻).
- Therefore, it is not a superoxide.

### Step 4: Conclusion
Based on the analysis, the only compound that contains the superoxide ion (O₂⁻) is **CsO₂ (Cesium superoxide)**.

### Final Answer
The superoxide among the given options is **CsO₂ (Cesium superoxide)**.

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