Diamond & Graphite

This lesson covers:

  1. The definition of an 'allotrope'
  2. The structure and properties of diamond and graphite

Two substances made from the same element, that are in the same physical state, but that have different structures, are called .

allotropes

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1

Select two allotropes of solid carbon from this list:

Graphite

Diamond

Silicone dioxide

Carbon dioxide

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tiny / giant / lattice / cube / carbon / silicon


Diamond and graphite are examples of covalent molecular structures. 


Both are made from the element arranged into a large regular repeating .

giant
carbon
lattice

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3

Which of the following statements are true of diamond?

Each carbon atom is bonded to 4 other carbon atoms

Each carbon atom is bonded to 3 other carbon atoms

It conducts electricity

It is made up of silicon and oxygen

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Diagram showing the atomic structure of diamond with carbon atoms.

Which structure is shown in the image?

Diamond

Graphite

Carbon

Glass

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Diagram showing the structure of graphite with layers of carbon atoms connected by covalent bonds and weak intermolecular forces.

Which structure is shown in the image?

Glass

Carbon

Diamond

Graphite

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In diamond, each atom is bonded to other atoms via covalent bonds. 


This forms a regular 3D lattice which is very strong, and has very melting and boiling points.

carbon
4
high

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3

Can diamond conduct electricity?

Yes

No

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Diagram showing the structure of graphite with carbon atoms bonded to three other carbon atoms forming 2D layers of repeating hexagons.

Unlike diamond, the carbon atoms in graphite each bond to other carbon atoms.


This arranges the graphite into 2D layers made up of repeating hexagons.

3

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Diagram showing the structure of graphite with delocalised electrons able to move freely and conduct electricity.

able / unable / localised / delocalised


Graphite is to conduct electricity.


This is because each carbon atom has one electron, which can move freely, and so is able to carry charge. 

able
delocalised

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Diagram showing the 2D layers of graphite with weak intermolecular forces holding them together.

Graphite is a lot softer than diamond. 


This is because the 2D layers of graphite stack on top of each other with only weak intermolecular forces holding them together.


This means the layers can slide over each other, making graphite easier to break.