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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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