which of the following repesents correct order of conductivity in solids ?

Options

A. `k_("metals")gtgtk_("insulators")lt k_("semiconductors")`
B. `k_("metals")ltltk_("insulators")lt k_("semiconductors")`
C. `k_("metals").,k_("semiconductors")gt k_("insulations ")=zero`
D. `k_("metals").,k_("semiconductors")gt k_("insulations ")nezero`

Explanation

To determine the correct order of conductivity in solids, we need to analyze the conductivity of different types of materials: metals, semiconductors, and insulators.

### Step-by-Step Solution:

1. **Understanding Conductivity**:
- Conductivity (κ) is the ability of a material to conduct electric current. It is the inverse of resistivity (ρ), which means higher conductivity indicates lower resistivity.

2. **Conductivity of Metals**:
- Metals have a very high conductivity due to the presence of free electrons that can move easily throughout the material. This allows metals to conduct electricity efficiently.

3. **Conductivity of Semiconductors**:
- Semiconductors have a moderate level of conductivity. Their conductivity can be influenced by temperature and the presence of impurities (doping). While they conduct better than insulators, their conductivity is significantly lower than that of metals.

4. **Conductivity of Insulators**:
- Insulators have very low conductivity because they lack free charge carriers (electrons). This makes it difficult for them to conduct electricity.

5. **Order of Conductivity**:
- Based on the above understanding, we can establish the order of conductivity from highest to lowest:
- Metals > Semiconductors > Insulators

6. **Conclusion**:
- Therefore, the correct order of conductivity in solids is:
- **Metals > Semiconductors > Insulators**

### Final Answer:
The correct order of conductivity in solids is:
**Metals > Semiconductors > Insulators**