Ionic Compounds: Characteristic Property

Ionic compounds are formed through the electrostatic attraction between oppositely charged ions (cations and anions). This attraction creates a strong bond.

• Strong electrostatic forces between ions: This is the defining characteristic. These forces hold the ions together in a rigid crystal lattice structure.

Analysis of Other Options

The strength of the electrostatic forces directly influences other properties:

• Melting Point: Because the forces holding the ions together are very strong, a large amount of energy is required to break these bonds and melt the compound. Therefore, ionic compounds typically have high melting points, not low.
• Solubility in Water: Water is a polar solvent. Its polar molecules can surround and stabilize the individual ions, overcoming the lattice energy for many ionic compounds. Thus, most ionic compounds are soluble in water, not insoluble.
• Electrical Conductivity (Molten State): In the solid state, ions are fixed in the lattice and cannot move, so solid ionic compounds do not conduct electricity. However, when melted (molten state) or dissolved in water, the ions become mobile and can carry charge, allowing for good electrical conductivity. Therefore, they exhibit good electrical conductivity in the molten state, not poor.

Based on this analysis, the fundamental characteristic property is the strong electrostatic attraction between the ions.