Question: what is the strongest meterial and why?

Ee Lyn Lim answered on 20 Jun 2013:

It’s actually graphene! Like diamond, it’s made of carbon, but instead of having the carbon atoms arranged in a tetrahedral shape (kind of like a pyramid, except with a triangular base) the atoms are arranged in hexagons, like the stitching on a football.

The lovely thing about carbon atoms is, if you arrange them in a regular hexagonal pattern like that, all the electrons from all the carbon atoms are free to run all over the pattern, rather than being stuck with any particular atom – it’s known as electron delocalisation. What that does is it creates a layer of negative charge over the surface of the graphene, whereas all the atomic nuclei, which make up the hexagonal shapes, have a positive charge. So you’ve got a material that’s got really strong electrostatic forces holding it together, which is why it’s so strong! The scientists who made it said this: ‘It would take an elephant, balanced on a pencil, to break through a sheet of graphene the thickness of Saran Wrap’!

But really graphene is just a single-atom layer of carbon atoms – the scientists who discovered it got it this thin by peeling cellophane tape off some graphite, which is pencil lead! Because it’s such a thin layer, we can also make it into other shapes, like rolling it into a hollow tube – that forms carbon nanotubes which are even stronger than just a plain sheet. And if you weave those tubes together, like a piece of cloth…? Indestructible! 🙂