Page 4 - Curriculum Visions Dynamic Book

An element is a substance that cannot be broken down into a simpler substance by any known means. Each of the
92 naturally occurring elements is therefore one of the fundamental materials from which everything in the Universe is made. This book is about the elements
lead and tin.
Lead
You have probably noticed the word lead most commonly in petrol stations. Here much of the fuel is called lead-free, or unleaded. This tells us two important things about lead: it is very useful (otherwise lead would not have been put in petrol), and it has unpleasant side effects (otherwise why would such a fuss be made of taking lead out of petrol?).
In fact, people have always had a love-hate relationship with this important and commonly used metal. For example, lead was used by ancient peoples to make colouring pigments (often white) for paints. More disastrously, they also used lead in cosmetics. From this kind of use lead was absorbed into the body, where
it acted as a poison. Lead in petrol could also have a similar effect, which is why it is now not used in fuels. But lead is also waterproof, easy to shape and does not corrode. It was just the thing for making water pipes – until it was discovered that lead dissolves in soft water and so contaminates the water.
The chemical symbol for lead is Pb. This is derived from plumbum, the Latin word for lead.
Perhaps the most confusing thing
about this soft grey metal is that one of the
 Snail-eating utensils cast in pewter.
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