It is made up of 9 carbon atoms (the light blue ones), 4 oxygen atoms (the red ones), and 8 hydrogen atoms (the white ones), put together into this particular shape.

Atoms don't actually look like smooth colorful spheres, more like fuzzy nondescript balls (sort of). But it is easier to see how they fit together this way.

Lots of different molecules exist, from small ones with just a few atoms to large ones with hundreds of atoms. (Can you think of a molecule with lots of atoms? If not, see the bottom of this page for an example of a common one.)

We are interested in a couple of molecules (or molecule fragments) made purely of carbon, that were discovered not that long ago:


To design a material, you need to know what is inside it. Everything is made up of atoms, and these atoms join together into molecules. For example, here is aspirin, a molecule which happens to reduce the pain of headaches.

buckyballs, 60 carbon atoms arranged in hexagons and pentagons and resembling a soccer ball   (also called buckminsterfullerenes)

nanotubes, tubes of carbon atoms arranged in hexagons and resembling rolled-up chicken wire   (also called buckytubes - this is a very short one: they are usually much longer than this)

Actually, we are even more interested in the smaller cousins of the above, as these are more rigid:

The reason we are interested in these molecules is that they are very strong (nanotubes have been estimated to be 50 times stronger than steel) and resilient (simulations have shown that even massively deformed buckyballs and nanotubes easily and quickly bounce back to their original shapes).

Nanotubes have extremely high tensile strength, which is strength when being stretched. On the next page we will begin to arrange these in such a way that they also have high strength when being compressed and bent.

Molecule Fragments: actually the nanotubes above are not molecules, they are molecule fragments, as the ends are unstable. Carbon atoms are stable with four joins. The carbon atoms in buckyballs and nanotubes usually have three joins, but one of them is a double-join, making four joins in all. The ends above are missing a join, and will tend to react more with other molecules in the environment, such as air and water.   (A join in this case is a covalent bond between one atom and another, where each atom shares electrons with its neighbor.)
More accurately, the joins in nanotubes are aromatic joins, which is sort of like each join being 1⅓ singles. Three bonds x (1⅓) = 4.

Did you think of a molecule with lots of atoms? An example of a common molecule with thousands of atoms is DNA:

36 carbon atoms also arranged in hexagons and pentagons

thinner nanotubes (again, a very short one)

Here is a small fragment of DNA, shown as a stereo image ...

... just relax your eyes and let the two images merge to see it in 3D.

The Double Helix

Photo from Issue 18 of The Photon (University of Maryland)