Define the term nanotechnology, and state why it is of interest to chemists.

(i)     Describe the structure of carbon nanotubes.

(ii)     State one physical property of carbon nanotubes.

Suggest two concerns about the use of nanotechnology.

nanotechnology involves research and technology developments at the 1 nm to 100 nm range;

structures with novel properties (because of their small size);

ability to manipulate on the atomic scale;

Overlap here between definition and matters of interest, so accept any two.

(i)     (main) cylinder consists of carbon hexagons / OWTTE;

pentagons close structures/tubes at ends / OWTTE;

Marks may also be scored by means of a suitable diagram showing above.

(ii)     high tensile strength / low density / high thermal conductivity / (electrical) conductors / (electrical) semi-conductors / high melting points;

health concerns / concern that the human immune system will be defenceless against particles on the nanoscale;

potential toxicity of materials / toxicity regulations are difficult (to apply);

possible explosive nature of large scale manufacture of nanoparticles;

political issues;

Apply OWTTE throughout.

Many candidates were able to define the term nanotechnology and scored M1 but only about half managed to score M2.

In (b)(i), although most mentioned hexagons and pentagons, many failed to mention cylinders and ends of tubes.

In (c) many candidates were able to score at least one mark, some scored both marks but, again, some vague answers were seen.