What is salt?

Sodium chloride, also known as common salt or table salt, is an ionic chemical compound with the formula NaCl. This means that for every gramme of salt, almost 40 per cent is sodium (Na) and over 60 per cent is chlorine (Cl).

Salt occurs naturally in our seas and when pools of sea water become enclosed the sun causes the water to evaporate. Over a period of millions of years, this salt bed is then covered with other sediment leaving a layer of rock salt, otherwise known as halite.