Common table salt, without any of the extra ingredients that may be added to the retail food product, is a compound comprised of the metallic element sodium and the non-metallic element chlorine. The chemical name for pure table salt is sodium chloride, and it is represented by the chemical formula NaCl, which indicates that each molecule consists of one sodium atom bonded to a chlorine atom. Because the bond holding the two atoms together is an ionic bond, sodium chloride belongs to the class of chemical compounds called ionic salts or ionic compounds.
Most supermarket versions of table salt are about 97 to 99 percent refined sodium chloride, with magnesium carbonate or sodium aluminosilicate added to enable the product to flow freely from a salt shaker. Certain additives, such as iodine compounds, may also be added to the retail sale product to address health concerns. Iodine deficiency has been linked to mental retardation, and iodized table salt has been shown to reduce iodine deficiency disorders. The amounts and types of additives that can become part of consumer-use table salt vary from country to country.