Is the conductivity of ionic solids due to the presence of ions ?

Answer

To determine whether the conductivity of ionic solids is due to the presence of ions, we can analyze the properties of ionic solids and how they conduct electricity.

### Step-by-Step Solution:

1. **Understanding Ionic Solids**:
- Ionic solids are composed of positively and negatively charged ions held together by strong electrostatic forces (ionic bonds).

2. **Conductivity in Solids**:
- Conductivity refers to the ability of a material to allow the flow of electric current. In solids, this typically occurs through the movement of charged particles.

3. **Presence of Ions**:
- While ionic solids contain ions, these ions are fixed in a rigid lattice structure at room temperature. This means that they cannot move freely.

4. **Mobile Ions**:
- For a material to conduct electricity, there must be mobile charge carriers. In ionic solids, the ions are not mobile in their solid state. Therefore, they cannot contribute to conductivity.

5. **Conductivity in Molten State or Aqueous Solution**:
- When ionic solids are melted or dissolved in water, the rigid lattice breaks down, allowing the ions to move freely. In this state, the ions can carry electric current, leading to conductivity.

6. **Conclusion**:
- The conductivity of ionic solids is not due to the presence of fixed ions in the solid state, but rather due to the mobility of ions when the solid is melted or dissolved. Hence, the answer to the question is no; conductivity is due to mobile ions, not just the presence of ions.