Here's why:

* Ionic Compound: Silver nitrate is an ionic compound, meaning it's made of positively charged silver ions (Ag+) and negatively charged nitrate ions (NO3-).

* Solid State: In its solid state, the ions are held rigidly in a crystal lattice structure. The ions are not free to move, so there is no flow of charge, and therefore no conductivity.

However, silver nitrate becomes a strong conductor when dissolved in water:

* Dissociation: When dissolved in water, the ionic bonds in silver nitrate break, and the ions become free to move around. This process is called dissociation.

* Electrolyte: The solution now contains a high concentration of mobile ions, making it a strong electrolyte. This means it can conduct electricity very well.

In summary:

* Solid silver nitrate: Not a conductor

* Aqueous silver nitrate solution: A strong conductor