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Atomic Structure

Giant Molecules.

A covalently bonded substance containing a huge number of atoms
 is called a giant molecule or a giant covalent lattice.

There are four examples of molecules forming giant structures.
They are silicon, silicon dioxide
 and two forms of carbon called diamond and graphite
(polymers are a different kind of large molecule).

When two (or more) forms of an element
exist in the same physical state, they are called allotropes.
Diamond and graphite are allotropes of carbon.
Carbon can exist as fullerenes in addition to diamond and graphite.

Carbon and silicon are both in group 4 of the periodic table.
They both need to form 4 bonds with themselves or other elements.
They have valency 4.
Valency is the combining power of an atom.

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Copyright © 2008 Dr. Colin France. All Rights Reserved.