What residue is left after sodium chloride heated?

Sodium chloride (NaCl), commonly known as table salt, does not leave any residue when heated. When heated, NaCl undergoes thermal decomposition at temperatures above 800°C. This process results in the separation of sodium (Na) and chlorine (Cl) atoms. However, these atoms recombine upon cooling, reforming sodium chloride.

Therefore, heating sodium chloride does not produce any residual material; it remains as sodium chloride.