Sodium chloride NaCl , commonly known as table salt, has a crystal structure called the face-centered cubic FCC lattice or cubic close-packed CCP 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 three-dimensional lattice.The crystal structure of sodium chloride significantly affects its physical and chemical properties:1. High melting and boiling points: The strong electrostatic forces between the positively charged sodium ions and the negatively charged chloride ions create a stable lattice structure. This ionic bonding requires a large amount of energy to break, resulting in high melting 801C and boiling 1413C points for NaCl.2. Brittleness: The ionic bonds in the NaCl lattice are non-directional, meaning they have equal strength in all directions. When a force is applied to the crystal, the ions may shift, causing ions with like charges to come into close proximity. This leads to repulsion, which can cause the crystal to fracture or break. As a result, NaCl is brittle.3. Solubility in water: Sodium chloride is highly soluble in water due to the polar nature of water molecules. The positively charged hydrogen atoms in water are attracted to the negatively charged chloride ions, while the negatively charged oxygen atoms are attracted to the positively charged sodium ions. This interaction leads to the dissociation of NaCl into its constituent ions, which become surrounded by water molecules hydration .4. Electrical conductivity: In its solid state, NaCl does not conduct electricity because the ions are held in a fixed lattice and cannot move freely. However, when NaCl is dissolved in water or melted, the ions become mobile and can carry an electric charge, making the solution or liquid conductive.5. Formation of cubic crystals: The face-centered cubic lattice structure of NaCl leads to the formation of cubic-shaped crystals. This is due to the symmetrical arrangement of ions in the lattice, which results in the regular, geometric shape.In summary, the crystal structure of sodium chloride plays a crucial role in determining its physical and chemical properties, such as high melting and boiling points, brittleness, solubility in water, electrical conductivity, and the formation of cubic crystals.