${{\text{C}}_{{\text{60}}}}$ fullerene consists of a simple molecular structure. Silicon dioxide, ${\text{Si}}{{\text{O}}_{\text{2}}}$, can be described as a giant covalent (macromolecular) structure. Which statements are correct?

I.     Each carbon atom in ${{\text{C}}_{{\text{60}}}}$ fullerene is bonded in a sphere of 60 carbon atoms, consisting of pentagons and hexagons.

II.     Each O–Si–O bond angle in ${\text{Si}}{{\text{O}}_{\text{2}}}$ is 180°.

III.     ${\text{Si}}{{\text{O}}_{\text{2}}}$ is insoluble in water.

A.     I and II only

B.     I and III only

C.     II and III only

D.     I, II and III

B

One respondent stated that statement I. could have been better worded and stated that bonded in a sphere could be taken to mean that each atom is bonded in a sphere rather than a sphere made of all 60 atoms. This is a fair comment. 41.13% of candidates got the correct answer B and the question was the sixth hardest question on the paper.