Section 1 of 7What fullerenes are
Caged carbon
- Caged carbon Fullerenes are molecules made only of carbon atoms joined in rings, mostly hexagons, that curve round to form hollow spheres, tubes or other cage shapes.
- They are allotropes of carbon, like diamond and graphite.
Different sizes
- Different sizes Different fullerenes contain different numbers of carbon atoms, so there is a whole family of them.
Simple molecular
- Simple molecular Each fullerene is a discrete molecule, so only weak forces act between separate fullerene molecules.
Section 2 of 7Buckminsterfullerene
The first fullerene
- The first fullerene Its formula is C60: sixty carbon atoms forming a hollow ball with the same pattern as a football.
- The surface is made of 20 hexagons and 12 pentagons.
Properties
- Properties It is a molecule, so its melting and boiling points are much lower than those of diamond.
- The weak forces between the balls let them roll over each other, so it can act as a lubricant.
Section 3 of 7Carbon nanotubes
Structure
- Structure A carbon nanotube is a sheet of hexagonally arranged carbon atoms rolled into a very thin cylinder, a few nanometres across.
- The tube is long compared with its width.
Properties
- Properties Very high tensile strength because of the strong covalent bonds in the hexagonal network.
- Conducts electricity and heat, since each carbon has a delocalised electron.
Uses
- Uses Reinforcing materials such as tennis rackets and bicycle frames without adding much mass, and in electronics.
Section 4 of 7Linking property to use
| Property | Use |
|---|---|
| Hollow cage shape that can enclose other molecules | Targeted drug delivery: a drug is trapped inside and carried to a specific place in the body. |
| Very large surface area | Holding catalyst particles on its surface so that reactants can reach them easily. |
| Weak forces between separate fullerene molecules | Lubricants, since the molecules slide or roll past each other. |
| High tensile strength (nanotubes) | Strengthening sports equipment and other composite materials. |
| Electrical conductivity (nanotubes) | Tiny wires and components in electronic circuits. |
Section 5 of 7How to write the answer
1
Name the fullerene, for example buckminsterfullerene or a nanotube.
2
State the structural feature, such as 'hollow cage' or 'cylinder of hexagons'.
3
State the property that follows from the feature, for example the ability to trap a molecule or high tensile strength.
4
State the use and make sure it matches that property, not another one.
Section 6 of 7Key terms
| Term | Meaning |
|---|---|
| Fullerene | A molecule made of carbon atoms arranged in a hollow cage, sphere or tube. |
| Buckminsterfullerene | The fullerene C60, a hollow ball of 60 carbon atoms. |
| Carbon nanotube | A fullerene shaped as a very thin cylinder of carbon atoms. |
| Tensile strength | The ability of a material to resist being pulled apart. |
| Catalyst | A substance that speeds up a reaction without being used up. |
| Nanometre | One billionth of a metre. |
Section 7 of 7Exam technique
1
Matching the wrong property to a use — drug delivery relies on the hollow shape, not on the strength.
2
Saying fullerenes are giant covalent structures; they are molecules with weak forces between them.
3
Writing that buckminsterfullerene has 60 hexagons — it has 20 hexagons and 12 pentagons.
4
Forgetting that nanotubes are fullerenes too, rolled into cylinders.
5
Saying nanotubes conduct because they contain ions; it is delocalised electrons.