Atomic Structure

What  is the Structure of Graphite?

Whenever 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.

Graphite consists of many flat layers of hexagons
(like a wire fence).
The layers are called graphene sheets.
Each carbon atom is joined to three other carbon atoms.
Each layer is itself a giant molecule
with very strong covalent bonds.

Carbon is in group 4 of the periodic table
and so it has four electrons in its outer shell.
Three electrons are used for bonding in the graphene sheet.
The fourth electron between the layers is delocalised
(it is a free electron).

Between the layers the bonds are weak. Free electrons between
the layers allows graphite to conduct electricity and heat.

The layers can easily slide over each other making graphite soft
and slippery and an excellent lubricant (like oil).

See also carbon fibres and fullerenes.


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