What is the chemical formula for table salt?
Quick answer
The chemical formula for common table salt is NaCl, short for sodium chloride. It contains one sodium (Na) atom for every chlorine (Cl) atom, held together by an ionic bond. Sodium’s symbol comes from its Latin name, natrium. Salt forms cube-shaped crystals and dissolves easily in water.
Two dangerous elements, one safe compound
| Element | On its own | In salt |
|---|---|---|
| Sodium (Na) | A soft, silvery metal that reacts violently with water | Gives up one electron, becoming Na⁺ |
| Chlorine (Cl) | A toxic, greenish-yellow gas | Gains that electron, becoming Cl⁻ |
The positive and negative ions attract each other strongly, forming an ionic bond. Billions of ions stack into a cubic crystal lattice, which is why salt grains look like tiny cubes under a magnifying glass. Compare this with how atoms share electrons in what a covalent bond is.
Salt by the numbers
| Property | Value |
|---|---|
| Melting point | 801 °C |
| Sodium content | About 40% of salt’s weight |
| Dissolves in water | About 360 g per liter at room temperature |
| Ocean salinity | About 3.5% dissolved salts, mostly NaCl |
Where salt comes from
- Evaporating seawater in shallow ponds (sea salt)
- Mining rock salt (halite) from underground deposits left by ancient seas
- Pumping water into salt beds and evaporating the brine
Types of table salt
| Type | Notes |
|---|---|
| Iodized salt | Has added iodine to prevent iodine deficiency |
| Sea salt | Contains small amounts of other minerals |
| Kosher salt | Larger flakes, easy to pinch |
| Himalayan pink salt | Rock salt colored by traces of iron oxide |
All are mostly sodium chloride.
Beyond the kitchen
Most salt produced worldwide isn’t eaten. It’s used to make chlorine and sodium hydroxide for industry, and to de-ice roads in winter, since salt lowers water’s freezing point; see what temperature water freezes at.
Salt was once valuable enough to be money; see was salt ever used as money.
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