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Why does sodium chloride not consist of separate NaCl molecules?

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Two diagrams show the three-dimensional structure of a methane molecule: panel A uses a ball-and-stick model with a central carbon atom connected to four hydrogen atoms in a tetrahedral arrangement, while panel B illustrates the bond angle of 109.5 degrees and bond length of 1.09 angstroms between carbon and hydrogen atoms. — chemical compound Methane, in which four hydrogen atoms are bound to a single carbon atom, is an example of a basic chemical compound. The structures of chemical compounds are influenced by complex factors, such as bond angles and bond length.

Sodium chloride (NaCl) does not consist of separate molecules because it is an ionic compound rather than a covalently bonded one.12

In chemistry, substances that form individual molecules are typically held together by covalent bonds, where electrons are shared between specific atoms. In contrast, sodium chloride is composed of a three-dimensional crystalline array of alternating positive sodium ions (Na⁺) and negative chloride ions (Cl⁻).213

The bonding in NaCl is ionic, meaning it arises from the electrostatic force of attraction between oppositely charged ions. Because this electrostatic attraction is nondirectional, each ion tends to be surrounded by the maximum number of oppositely charged neighbors, resulting in an extended lattice structure rather than discrete, isolated units. Consequently, the chemical formula "NaCl" represents the simplest ratio of ions—an empirical formula—rather than a molecular formula.24356