Seawater & its Richness
 The composition of seawater
 The sea water of Cancale,
 Brittany, France
The benefits of seawater

The composition of seawater
On average, seawater in the world's oceans has a salinity of about 3.5% (35 g/L). This means that every kilogram (roughly one liter by volume) of seawater has approximately 35 grams of dissolved salts -predominantly Sodium Chloride ions: Na+, Cl−. Seawater contains more dissolved ions than all types of freshwater.

Although the vast majority of seawater has a salinity varying between 3.1% and 3.8%, seawater is not uniformly saline throughout the world. Where mixing occurs with fresh water runoff from river mouths or near melting glaciers, seawater can be substantially less saline. The most saline open sea is the Red Sea, where high rates of evaporation, low rates precipitation & river inflow, and confined circulation result in unusually salty water.
DID YOU KNOW:     Most of this salt in the sea has been released from volcanic activity or extracted from cool, igneous rocks!!!

The pH of seawater is limited to the range 7.5 to 8.4.


Seawater composition (by mass) (salinity = 35)

Element % Element %
Oxygen 85.84 % Sulfur 0.091 %
Hydrogen 10.82 % Calcium 0.04 %
Chloride 1.94 % Potassium 0.04 %
Sodium 1.08 % Bromine 0.0067 %
Magnesium 0.1292 % Carbon 0.0028 %

96.7% of the contents of sea water is pure water. The majority of what remains is composed of Sodium Chloride, however, the presence of several trace elements, despite their small presence, is particularly important.

Seawater does not remain in one position. Tidal and oceanic currents move great masses of it around the world. As a result, the amounts of trace elements and minerals are not constant and depend on factors such as geographical location, volcanic activity, pollution, etc.