When sodium (Na) and chlorine (Cl) react, they form sodium chloride (NaCl), also known as table salt. The reaction between sodium and chlorine is a typical example of an ionic bond formation. Both sodium and chlorine have highly contrasting electronegativities. Sodium has a low electronegativity, meaning it readily gives up its valence electron, while chlorine has a high electronegativity, indicating its strong attraction for electrons.

During the reaction, sodium loses its outermost electron to chlorine, resulting in the formation of positively charged sodium ions (Na+) and negatively charged chloride ions (Cl-). These oppositely charged ions are then attracted to each other by electrostatic forces and form a stable ionic compound, sodium chloride. The arrangement of these ions in a regular crystal lattice results in the formation of salt crystals.

The reaction between sodium and chlorine can be represented as follows:

2Na(s) + Cl2(g) → 2NaCl(s)