Which of the following is a property of ionic compounds? 

Good conductor of electricity in aqueous state

Ionic compounds are brittle due to the strong bond between the positive and negative ions that form the compound. Additionally, ionic compounds are good conductors of electricity when in their aqueous state.

Detailed Explanation:
Ionic compounds are formed when atoms of a metal lose electrons to become positively charged ions, while atoms of a non-metal gain those electrons to become negatively charged ions. These oppositely charged ions are held together by strong electrostatic forces of attraction, forming a stable ionic bond. The strong ionic bonds give ionic compounds several distinct properties.

Properties of Ionic Compounds:

1. Brittleness:
   • Ionic compounds are brittle because the ions in the crystal lattice are strongly bonded. When pressure is applied, the ions shift, and if the ions of the same charge align, they repel each other, causing the compound to break.
   • For example, sodium chloride (NaCl) is brittle when hit with a hammer because the shift in ion alignment leads to the crystal shattering.
2. Electrical Conductivity in Aqueous State:
   • Ionic compounds can conduct electricity when dissolved in water (aqueous state) because the ions are free to move in the solution. This is known as electrolytic conductivity.
   • In their solid form, ionic compounds do not conduct electricity because the ions are not free to move. However, in an aqueous solution, the ions dissociate and move freely, allowing them to conduct an electric current. For example, salt (NaCl) dissolved in water conducts electricity.