AN OUTLINE PLAN FOR C60 WORKSHOPS (lower/upper primary)
The Sussex Fullerene Group, University of Sussex*
Falmer, Brighton, East Sussex. BN1 9QJ
* © based on workshop notes made by H. W. Kroto and J. P. Hare
(C60WS1.doc, last updated Dec. 1998)
Atoms, stars and space
Scientists believe that everything around us is made up of tiny building
blocks called atoms.
How big is an atom ? (talk about meters, centimetres, millionths etc. etc.)
Atoms are tiny - roughly a tenth of a billionth of a meter.
An apple for example, is composed of an unbelievable amount of atoms, and
even the tiniest speck of dust contains millions and millions.
On a sunny day the Sun shines very brightly. On a dark, cloudless night you
will see thousands of stars in the sky. It may be hard to believe, but these
stars are just like our own Sun but they are such a long distance away that
we only see them as tiny twinkling lights. Most of the atoms that go up to
make the things around us (including you !) have been made within these
stars. Sometimes these stars blow-up sending out atoms into space.
Eventually, these atoms join up to form new stars, perhaps planets and even us
- 'you are all star dust !'.
Diamond and Graphite
A diamond is a hard sparkling gem stone, while graphite (soft pencil lead)
is dark and messy. Despite these differences the two substances are made up
of the same tiny building blocks - carbon atoms.
Diamond :
The atoms in diamond are joined together very rigidly rather like a
builders scaffolding around a house - because of this diamond is very
strong.
Graphite :
In pencil graphite the atoms are arranged in layers, rather like pieces
of paper in a book. Its easy to tare out a page from a book and a
similar thing happens when we write with a pencil; - layers of atoms come
off and leave a mark on the paper.
Buckminsterfullerene
In 1985 scientists at Sussex University, near Brighton, UK and at the Rice
University in Texas USA, discovered that carbon atoms could also join-up to
form tiny balls, just a billionth of a meter in size. Scientists call a
billionth of a meter a nanometer.
There is a nice way of imagining just how small these carbon balls are ;
'the jump from the Earth to a football is the same as the jump,
down from a football to C60, the carbon ball' - that's how small it is !
Buckminsterfullerene is a football
The last picture is a particularly good one as the tiny carbon balls are
also exactly the same shape as a football. We will study the football in
more detail a little later on.
Why the funny name ?
Each ball is made up of 60 carbon atoms and so it is often called C60. It
also has a longer name - Buckminsterfullerene and sometimes it is even
called a Buckyball.
It was named after an American architect called Richard Buckminster Fuller
who designed dome like buildings that rather resemble the carbon balls.
Lets look at the football again
If we look at a picture of C60 what can you tell me about it ? (see picture)
some likely answers:
* its round(ish)
* has pentagons (5 sided faces), how many ? (answer: 12)
* has hexagons (6 sided faces), how many ? (answer: 20)
* looks like a football
It really is a tiny football of carbon. Lets have a look at the football,
and other shapes, in more detail :
Shapes and mathematical laws - Eulers Law
If we look at a cube, pyramid or football, each has a different number of
edges, corners and faces (point to a face, corner and edge, just to make
sure they are happy which is which) . A mathematician called Euler,
discovered a simple rule that links many different shapes. It is very simple :
The number of Corners plus number of Faces minus number of Edges equals TWO
we can write this : C + F - E = 2
But does it work ?
Cube
Lets try it for the cube (see pictures, or draw one up on the board)
How many corners does a cube have ? (answer: 8)
How many faces does a cube have ? (answer: 6)
How many edges does a cube have ? (answer: 12)
Lets see if this works :
Corners + Faces - Edges = 2
8 + 6 - 12 = 2 yes it worked !
Pyramid
Lets try it for the Egyptian Pyramid (which has a square base and triangular
sides)
How many corners, faces, edges ? etc.
C + F - E = 2
5 + 5 - 8 = 2.... again it works !
Football
So lets take a football. It is not too hard to count up the number of faces
and corners but it is quite hard to count up all the edges, there's so many
of them !
Lets use our rule (formula) to see if we can work out (predict) how many
edges there are without having to count them up first.
How many corners are there ? (answer: 60)
How many faces ? (answer: 12 pentagons and 20 hexagons = 32)
We have seen that Corners + Faces - Edges = 2 so
60 + 32 - Edges = 2
92 - Edges = 2
in other words, what number can we take away from 92 that will leave 2 ?
(answer 90)
Our mathematical rule has allowed us to predict something about the football
- it should have 90 Edges.
Count up the number of edges to see if it works !
(tip: postits might help to keep track of what's been counted)
Making a model of C60
Now that we have learned a little about the football and that C60 has the
same shape we will now have a go at making a model of this structure.
(don't give out the model kits just yet)
In the little bags we are going to give out there are enough bits to make up
a complete model of C60. Actually there are a few extra bits so you will
have some left over.
The little plastic straws need to be separated from each other (at the
moment they are in a block which easily comes apart). These straws fit into
the small black plastic pieces.
What do we know about C60 ?
it has :
60 Corners (the black 'atom' pieces in our model we are going to make)
90 Edges (the coloured straws)
it also has 12 five sided faces - pentagons
and 20 six sided faces - hexagons
although the hexagons can be side-by-side
the pentagons never touch each other
ADDITIONAL NOTES :
Things needed for the workshop :
• Football, best if the hexagons are a different colour to the pentagons
(which is often the case)
• One model kit for each participant
• Large (say 20 cm) cardboard models of a cube, pyramid etc.
• some pictures (see text)
• enough space and perhaps a helper for every 10 participants
TO BE READ AFTER ATTEMPTING TO MAKE A MODEL OF C60
A Buckyball Trick
I must admit that when I made my first model of C60 I found it quite hard.
However, later on I worked out a very simple trick to making it.
I will give you a clue:
C60 has 60 atoms, it also has 12 pentagons. Pentagons have 5 sides and 5
atoms.
Now 12 x 5 = 60, so in a way the Buckyball appears to be made up of atoms
just in pentagons !
Some articles :
A new form of carbon is born, Jim Baggott, New Scientist, 13 Oct. 1990
Great Balls of Carbon, Jim Baggott, New Scientist, 6 July 1991
Buckyballs bounce into action, Jonathan Crane, Chemistry Review, Jan 1995
Some C60 web sites, Chemistry Review, Sept. 1997, Jason Lynam, p.6-7
Lunch with Sir Harry, Chemistry Review, Sept. 1997 Richard Beatty, Simon
Evans, Cher Thornhill p.12-13.
Buckyballs and Beyond, The Science Museum, Exhibition 6 May - 11 Oct. 1998
Books :
Perfect Symmetry, Oxford University Press 1994, Jim Baggott, ISBN 0 19
8557906
The Most Beautiful Molecule, An Adventure in Chemistry, Aurum Press 1994,
Hugh Aldersey-Williams
Designing the Molecular World - Chemistry at the frontier, Princeton
University Press 1994, Philip Ball, ISBN 0 691 00058 1
WEB SITES OF INTEREST:
1) See the Stories of Science section of this web site.
2) For information on the 1996 Chemistry Nobel Prize go to :
www.nobelprize.org
Model kits, where you can buy them from :
Small C60/C70 model kit packs,
(~£ 2 each) Cochranes of Oxford Ltd, Leafield,Oxford. OX8 5NT.
Tel. 01993 878641
Large strong C60 kits,
(~£ 20 each) Molymod,
Spiring Enterprises Ltd, Billingshurst, West Sussex. RH14 9HF.
Tel. 01403 782387
* © based on workshop notes made by H. W Kroto and J. P Hare
(C60WS1.doc, last updated Dec. 1998)
Dr Jonathan Hare, E-mail: jphcreativescience@gmail.com
NOTE: Although none of the experiments shown in this site represent a great hazard, neither the Creative Science Centre,
Jonathan Hare nor The University of Sussex can take responsiblity for your own experiments based on these web pages.
THE CREATIVE SCIENCE CENTRE
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