Sodium chloride NaCl , commonly known as table salt, has a face-centered cubic FCC crystal structure, also known as the rock salt structure. In this arrangement, each sodium ion Na+ is surrounded by six chloride ions Cl- , and each chloride ion is surrounded by six sodium ions. This results in a highly symmetrical and efficient packing of the ions, forming a stable crystal lattice.The crystal structure of NaCl is closely related to its properties and applications:1. High melting and boiling points: The strong electrostatic attraction between the positively charged sodium ions and the negatively charged chloride ions in the crystal lattice leads to high melting 801C and boiling points 1413C of NaCl. This makes it suitable for use in high-temperature applications, such as in the production of ceramics and glass.2. Solubility in water: The polar nature of water molecules allows them to interact with the charged ions in the NaCl crystal lattice, breaking the ionic bonds and dissolving the salt. This solubility is a key property for many applications, including food preservation, water softening, and as an electrolyte in various chemical processes.3. Electrical conductivity: In its solid state, NaCl is an insulator, as the ions are held in a fixed position within the crystal lattice. However, when dissolved in water or melted, the ions become free to move, allowing the solution or liquid to conduct electricity. This property is essential for applications such as electroplating and the production of chlorine and sodium hydroxide through the electrolysis of brine.4. Brittleness: The ionic bonds in the NaCl crystal lattice are strong but also directional, meaning that they are not easily able to shift or rearrange when subjected to stress. This results in the brittleness of NaCl crystals, which can be easily cleaved along specific planes.5. Taste: The distinct taste of NaCl is due to the interaction of the sodium and chloride ions with the taste receptors on the human tongue. This property makes it a widely used seasoning and flavor enhancer in the food industry.In summary, the face-centered cubic crystal structure of sodium chloride is responsible for its characteristic properties, such as high melting and boiling points, solubility in water, electrical conductivity, brittleness, and taste. These properties make NaCl suitable for a wide range of applications, from food seasoning to industrial processes.