To determine which of the given materials has a conductivity in the order of \(10^{-4} \, \text{ohm}^{-1}\text{cm}^{-1}\), we need to analyze the conductivity ranges of conductors, insulators, and semiconductors.
### Step-by-Step Solution:
1. **Understanding Conductivity**:
- Conductivity (\(\sigma\)) is a measure of a material's ability to conduct electric current. It is the inverse of resistivity (\(\rho\)).
- The general relationship is given by:
\[
\sigma = \frac{1}{\rho}
\]
2. **Conductivity Ranges**:
- **Conductors**: Have high conductivity, typically in the range of \(10^2\) to \(10^8 \, \text{ohm}^{-1}\text{cm}^{-1}\).
- **Insulators**: Have very low conductivity, usually around \(10^{-11} \, \text{ohm}^{-1}\text{cm}^{-1}\) or lower.
- **Semiconductors**: Have intermediate conductivity, generally in the range of \(10^{-5}\) to \(10^{6} \, \text{ohm}^{-1}\text{cm}^{-1}\).
3. **Analyzing the Options**:
- We need to find a material whose conductivity falls within the range of \(10^{-4} \, \text{ohm}^{-1}\text{cm}^{-1}\).
- From the ranges established:
- Conductors are too high.
- Insulators are too low.
- Semiconductors can potentially fit this range.
4. **Identifying Specific Materials**:
- **NaCl (Sodium Chloride)**: As an ionic solid, it acts as an insulator in solid state, thus having low conductivity.
- **Sodium Metal**: A good conductor, with conductivity much higher than \(10^{-4} \, \text{ohm}^{-1}\text{cm}^{-1}\).
- **Diamond**: A non-metallic solid with no free charge carriers, thus it acts as an insulator.
- **Germanium**: A semiconductor, which typically has conductivity in the range of \(10^{-5}\) to \(10^{-6} \, \text{ohm}^{-1}\text{cm}^{-1}\), making it a candidate for our required range.
5. **Conclusion**:
- The material that fits the conductivity order of \(10^{-4} \, \text{ohm}^{-1}\text{cm}^{-1}\) is **Germanium**, which is a semiconductor.
### Final Answer:
The correct answer is **Germanium**.
