The halogen derivative used as an antiseptic is:

Options

A. `CHCl_(3)`
B. `CHBr_(3)`
C. `"CCl"_(4)`
D. `CHI_(3)`

Answer

To determine which halogen derivative is used as an antiseptic, we can analyze the given compounds based on their properties and uses.

### Step-by-Step Solution:

1. **Identify the Compounds**: The question presents several halogen derivatives:
- Chloroform (CHCl₃)
- Bromoform (CHBr₃)
- Tetrachloromethane (CCl₄)
- Iodoform (CHI₃)

2. **Understand the Uses of Each Compound**:
- **Chloroform**: Primarily used as an anesthetic, not an antiseptic. It can relieve pain but is not suitable for antiseptic purposes.
- **Bromoform**: This compound is mainly used as a solvent and has applications in fire retardants. It is not recognized for antiseptic properties.
- **Tetrachloromethane (CCl₄)**: Known as carbon tetrachloride, it is used in fire extinguishers and as a solvent. It is considered carcinogenic and is not used as an antiseptic.
- **Iodoform**: This compound is known for its antiseptic properties. It decomposes to release iodine, which is effective in killing bacteria and fungi. It can also be used in tinctures of iodine, which are common antiseptics.

3. **Conclusion**: Among the compounds listed, **Iodoform (CHI₃)** is the halogen derivative that is used as an antiseptic.

### Final Answer:
The halogen derivative used as an antiseptic is **Iodoform (CHI₃)**.