Carbon nanotubes were first reported in 1991 by which scientist?

The correct answer is B, one billionth of a metre. The prefix nano stands for ten raised to the power minus nine, so one nanometre is one billionth of a metre, which is also ten angstrom, and nanotechnology is defined as work in the band of one to one hundred nanometres. Option A is wrong because one millionth of a metre is a micrometre or micron, the unit used for bacteria and for the thickness of a hair in older textbooks, and it is a thousand times larger than a nanometre. Option C is wrong because one thousandth of a metre is a millimetre, a length visible to the eye on any ruler. Option D is wrong because one trillionth of a metre is a picometre, a unit used for bond lengths inside a molecule and a thousand times smaller than a nanometre; the diameter of an atom is of the order of a hundred picometres.

The correct answer is B, Norio Taniguchi. The Japanese engineer Norio Taniguchi used the word nanotechnology in 1974 to describe machining to tolerances of a nanometre, and that is the coinage examiners expect. Option A is wrong, and it is the usual trap: Richard Feynman gave the famous lecture There's Plenty of Room at the Bottom in 1959, which set out the idea of building with individual atoms, but he never used the word, so he is credited with the concept and not with the term. Option C is wrong because K. Eric Drexler popularised the word through his book Engines of Creation in 1986 and through the phrase molecular nanotechnology, which is popularisation rather than coinage. Option D is wrong because Sumio Iijima reported carbon nanotubes in 1991, a landmark material but much later than the naming of the field.

The correct answer is A, Richard Feynman. The American physicist Richard Feynman delivered the talk There's Plenty of Room at the Bottom to the American Physical Society at Caltech in December 1959, in which he argued that there is no law of physics forbidding the manipulation of individual atoms, and the lecture is treated as the conceptual birth of nanotechnology. Option B is wrong because Albert Einstein, who died in 1955, worked on relativity, the photoelectric effect and Brownian motion, and had no part in this lecture. Option C is wrong because Gerd Binnig built the Scanning Tunnelling Microscope at IBM Zurich in 1981 with Heinrich Rohrer, giving the field its eyes rather than its founding idea. Option D is wrong because Harold Kroto shared the 1996 Nobel Prize in Chemistry for the discovery of fullerenes in 1985.

The correct answer is A, 12. Buckminsterfullerene, discovered in 1985, has sixty carbon atoms arranged in a closed cage of twenty hexagons and twelve pentagons, exactly the pattern of a stitched football, and the twelve pentagons are what allow a flat hexagonal sheet to curve into a closed ball. Option B is wrong because twenty is the number of hexagonal faces, which the question itself supplies, and swapping the two counts is the standard trap in this item. Option C is wrong because thirty two is the total number of faces of the molecule, twenty plus twelve, not the number of pentagons alone. Option D is wrong because sixty is the number of carbon atoms, that is the vertices of the cage, and the molecule was named after the architect Buckminster Fuller, whose geodesic domes it resembles.

The correct answer is C, 2010. Andre Geim and Konstantin Novoselov of the University of Manchester shared the Nobel Prize in Physics in 2010 for groundbreaking experiments on graphene, the single atom thick sheet of carbon they had lifted from graphite with ordinary adhesive tape. Option A is wrong because 2004 is the year of the isolation itself, and the gap between the discovery and the prize is the trap in this question. Option B is wrong because the Nobel Prize in Physics of 2008 went to work on broken symmetry and quarks, with no connection to graphene. Option D is wrong because the Nobel Prize in Physics of 2014 honoured the blue light emitting diode, a different materials achievement. Graphene is the strongest material yet tested, an excellent conductor and almost completely transparent.