Page 4 - Curriculum Visions Dynamic Book

An element is a substance that cannot be decomposed into a simpler substance by any known means. Each of the 92 naturally occurring elements is therefore one of the basic materials from which everything in the Universe is made. This book is about sodium and potassium.
Sodium
The white sparkling material that formed in salt pans of ancient Egypt was known as natron. We now call
it soda, and from this word the element sodium takes its name. The chemical symbol for sodium is Na, after the word natron.
Sodium is the seventh
most common element in the
Universe and comprises one-
thirtieth of the Earth’s crust.
On Earth its compounds give sea
water its salty taste. The Egyptians
used soda for embalming (much
as we now use salt to preserve food).
It was also used as a cleaning agent,
and for making glass and pottery. Today, sodium vapour lamps give the yellow– orange lights used for street illumination. Sodium is also vital to regulating many body processes.
For all these reasons, sodium remains one of the most widely used elements.
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 This orange flame is produced when sodium is burned. This is the colour you will see in many street lights.