- Salt in dry form is a chemical compound consisting of several crystallized ions.
- Salt comes in different forms and often occurs through chemical reactions.
- The word salt is often synonymous with ione compound. Salt is often dissolved easily in water. The sea is naturally salty, with about 3.5% salt.
- In oceanography, there is a tradition of expressing salinity not as a percentage, but in thousands of sums it is about the same as grams of salt per liter of seawater. The unit "psu" (practical salinity unit) is also used. Common salinity values for seawater and ocean water are 34-36.
- The salinity together with the temperature determines the density of seawater.
- The salinity of seawater is measured through conductivity. Conductivity is a property a substance has to conduct power.
By measuring the conductivity through the water, it is calculated how much salt is in the water.
