Page 5 - Curriculum Visions Dynamic Book

the bones of animals as well as the shells of snails, mussels and myriad other creatures contain calcium.
The bones of people also have calcium compounds in them. In fact, about one-fiftieth of the human body is made from calcium. Some uses
you may be able to guess, such as the formation of bones and teeth, but others are quite invisible to us, such as making our muscles
move!
But the element calcium is not just in natural things.
For example, it is also in the walls of the house around you. Its compounds make up the plaster used in walls, the cement that holds bricks firmly together and concrete that makes the base
for the house.
Magnesium
In many ways magnesium (symbol Mg) is very similar to calcium. Magnesium is one of the most important metals in the body, making up no less than one-fortieth of each and
every one of us. It is also a very important element in the makeup of all green plants.
Like calcium, magnesium is never naturally found alone but always as a compound combined with other elements. For example, it makes up the hard limestone-looking rocks of
magnesium carbonate called dolomite. Magnesium carbonate
is used as a filler in paper and as an antacid. And because magnesium burns with an intense white light, it is also useful
as a signal flare.
This book will introduce you to some of the wide range
of properties of calcium, magnesium and some of the compounds they form. It is a starting point for your exciting exploration into the
world of chemistry.
 Calcium metal burns with a brick-red coloured flame. The flame test is an important way to look for the presence of calcium.
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