Which of the following oxygen compound is not called oxide ?

Options

A. `OF_2`
B. `Cl_2O_7`
C. `ClO_2`
D. `BrO_2`

Explanation

To determine which of the following oxygen compounds is not called an oxide, we need to analyze the electronegativity of the elements involved in each compound. An oxide is typically formed when oxygen (with an electronegativity of 3.44) combines with another element that has a lower electronegativity.

Let's evaluate the options step by step:

1. **Identify the Compounds**:
We need to look at the given compounds and identify their components. The compounds typically mentioned in such questions are combinations of oxygen with other elements.

2. **Electronegativity Comparison**:
We will compare the electronegativity of oxygen with that of the other element in each compound. The general rule is that if the other element has a higher electronegativity than oxygen, the compound formed is not considered an oxide.

3. **Evaluate Each Option**:
- **Option 1: Oxygen and Fluorine (OF₂)**:
- Electronegativity of Fluorine (F) = 3.98
- Electronegativity of Oxygen (O) = 3.44
- Since Fluorine is more electronegative than Oxygen, OF₂ is not considered an oxide; it is a halogen compound.

- **Option 2: Chlorine and Oxygen (ClO)**:
- Electronegativity of Chlorine (Cl) = 3.16
- Since Chlorine is less electronegative than Oxygen, ClO is an oxide (specifically, it is called hypochlorous acid).

- **Option 3: Bromine and Oxygen (BrO)**:
- Electronegativity of Bromine (Br) = 2.96
- Since Bromine is less electronegative than Oxygen, BrO is also an oxide.

- **Option 4: Iodine and Oxygen (IO)**:
- Electronegativity of Iodine (I) = 2.66
- Since Iodine is less electronegative than Oxygen, IO is also an oxide.

4. **Conclusion**:
Based on the analysis, the only compound that does not qualify as an oxide is **Option 1: Oxygen and Fluorine (OF₂)**.

### Final Answer:
**The compound that is not called an oxide is: Oxygen and Fluorine (OF₂).**