How are the ions arranged in a crystal lattice of sodium chloride?

The correct answer highlights that the ions in sodium chloride are arranged in a giant structure held together by oppositely charged ions. This arrangement forms a crystal lattice, which is a repeating three-dimensional pattern. In sodium chloride, sodium ions (Na⁺) and chloride ions (Cl⁻) alternate in this lattice, creating a stable structure that maximizes the attractive forces between the positively charged sodium ions and the negatively charged chloride ions while minimizing repulsive forces.

The lattice structure results in the characteristic properties of salts like sodium chloride, including high melting and boiling points, and the ability to conduct electricity when melted or dissolved in water - because the ions are free to move. The orderly arrangement of the ions is fundamental to the integrity of the salt’s structure and is a key reason for its stability.

Other arrangements, such as linear formations, random arrangements, or flat molecular alignments, do not properly describe the nature of ionic compounds like sodium chloride, which fundamentally relies on strong electrostatic attractions and a three-dimensional lattice structure for its existence and properties.