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Atomic Structure

What  is the Structure of Graphite?

When you come across carbon as a reactant or electrode,
carbon means graphite not diamond.
It can be written C_(gr) but is usually written as just C.

The structure of graphite consists of many flat layers
of hexagons. The layers are called graphene sheets.
Each carbon atom in the layer is joined by strong
covalent bonds to only three other carbon atoms.
Compare this with the structure of diamond.
Each graphene sheet is itself a giant molecule.

Carbon is in group 4 of the periodic table and so it has
four electrons in its outer shell. Three of these electrons
are used for covalent bonding in the graphene sheet.

What  are the Properties of Graphite?

There are no covalent bonds between the layers and so
the layers can easily slide over each other making graphite
soft and slippery and an excellent lubricant (like oil).

The fourth electron between the layers is delocalised.
It is a free electron and these free electrons between the
layers allows graphite to conduct electricity and heat.

See also carbon fibres and fullerenes.

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