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Water - Solubility - Ions

The Sea.

The sea contains a large number of dissolved salts
which have come from the weathering of rocks.
The sea is a useful source
of raw materials including bromine and sea salt.

Sodium chloride is the main salt in the sea.
Other dissolved ions include sulfate, magnesium,
calcium, potassium, bromide and carbonate.

Sea salt can be made by allowing sea water to evaporate.
In hot countries the water is held in large open salt pans.
The water evaporates in the heat of the Sun leaving the
dissolved salt to crystallise from the solution. See also rock salt.

Salt is used as a flavouring and a preservative.
It is essential for humans and animals to have salt
in their diet but too much salt causes
high blood pressure and is bad for your health.

Government departments such as the Department of Health
and the Department for Environment, Food and Rural Affairs (Defra)
offer advice to people about food safety and risks

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