Which of the following metal oxides is antiferromagnetic in nature?

Options

A. `MnO_(2)`
B. `TiO_(2)`
C. `VO_(2)`
D. `CrO_(2)`

Answer

To determine which of the following metal oxides is antiferromagnetic in nature, we need to understand the properties of antiferromagnetic materials and analyze the given options.

### Step-by-Step Solution:

1. **Understanding Antiferromagnetism**:
- Antiferromagnetic materials are those in which the magnetic moments of atoms or ions align in opposite directions, resulting in a net magnetic moment of zero. This occurs due to the cancellation of opposing magnetic moments.

2. **Identifying Common Metal Oxides**:
- Common metal oxides include MnO2, TiO2, CoO, FeO, CrO2, and others. We need to evaluate their magnetic properties.

3. **Analyzing the Options**:
- **MnO2**: Manganese dioxide is known to exhibit antiferromagnetic behavior due to the arrangement of manganese ions.
- **TiO2**: Titanium dioxide typically shows paramagnetic or diamagnetic properties rather than antiferromagnetic.
- **CoO**: Cobalt(II) oxide is known to be antiferromagnetic.
- **FeO**: Iron(II) oxide also exhibits antiferromagnetic properties.
- **CrO2**: Chromium dioxide is known to be ferromagnetic.

4. **Conclusion**:
- Among the options, MnO2 is identified as an antiferromagnetic material. Therefore, the correct answer is **MnO2**.

### Final Answer:
The metal oxide that is antiferromagnetic in nature is **MnO2**.