In a sodium chloride NaCl crystal lattice, the arrangement of atoms is in a cubic pattern, specifically a face-centered cubic FCC lattice. This means that each sodium Na+ ion is surrounded by six chloride Cl- ions, and vice versa, forming a three-dimensional repeating pattern. The lattice structure is highly ordered, with alternating positive and negative ions.This arrangement results in several unique properties and chemical reactivity of sodium chloride:1. High melting and boiling points: The strong electrostatic forces of attraction between the positively charged Na+ ions and the negatively charged Cl- ions, known as ionic bonds, require a significant amount of energy to break. This leads to 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 of the same charge to come into close proximity. These like-charged ions repel each other, leading to the crystal breaking or shattering. This property is known as brittleness.3. Solubility in polar solvents: Sodium chloride is highly soluble in polar solvents like water. This is because the polar water molecules can interact with the charged Na+ and Cl- ions, breaking the ionic bonds and surrounding the individual ions in a process called hydration. The positive end hydrogen of the water molecule is attracted to the Cl- ions, while the negative end oxygen is attracted to the Na+ ions.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 dissolved in water or in a molten state, the Na+ and Cl- ions are free to move, allowing the substance to conduct electricity.5. Chemical reactivity: Sodium chloride is relatively stable and unreactive due to the strong ionic bonds holding the lattice together. However, it can participate in various chemical reactions, such as double displacement reactions with other soluble salts, or reactions with strong acids or bases. In these cases, the Na+ and Cl- ions can exchange partners or form new compounds.