Which of the following is a Pseudohalogen ?

Options

A. `C_(2)N_(2)`
B. `Cl_(2)`
C. `ICI`
D. `ClF_(3)`.

Explanation

To determine which of the given options is a pseudohalogen, we need to analyze the characteristics of each compound listed in the options. Pseudohalogens are compounds that exhibit similar properties to halogens, particularly in terms of their reactivity and the types of bonds they form.

### Step-by-Step Solution:

1. **Understanding Pseudohalogens**:
- Pseudohalogens are compounds that mimic the behavior of halogens. They often contain nitrogen or carbon and can form similar types of bonds as halogens.

2. **Analyzing the Options**:
- **Option 1: C2N2 (Cyanogen)**: This compound consists of two carbon atoms and two nitrogen atoms. Cyanogen has properties similar to halogens, such as forming salts with metals and exhibiting reactivity akin to that of halogens.
- **Option 2: Cl2 (Chlorine)**: This is a diatomic molecule of chlorine, which is a halogen itself, not a pseudohalogen.
- **Option 3: ICl (Iodine monochloride)**: This is a compound formed between iodine and chlorine, both of which are halogens.
- **Option 4: ClF3 (Chlorine trifluoride)**: This is a compound of chlorine and fluorine, both of which are halogens.

3. **Identifying the Pseudohalogen**:
- Among the options, C2N2 (cyanogen) is the only compound that exhibits pseudohalogen characteristics due to its structural and chemical properties that resemble those of halogens.

4. **Conclusion**:
- Therefore, the correct answer is **Option 1: C2N2**.

### Final Answer:
**C2N2 (Cyanogen) is a pseudohalogen.**