Answer: 20 hexagons and 12 pentagons in a soccer ball arrangement.
- A 20 hexagons and 12 pentagons in a soccer ball arrangement
- B Sixty separate hexagonal rings with little pentagons present
- C Twelve pentagonal rings alone with little hexagons in the structure
- D A diamond-like cubic lattice of sp<sup>3</sup>-hybridised carbon atoms
Correct answer: A. 20 hexagons and 12 pentagons in a soccer ball arrangement
Explanation: C<sub>60</sub> has exactly 20 hexagonal and 12 pentagonal faces; the pentagonal faces prevent infinite flat-sheet growth, curving it into a sphere.
Diamond's rigid 3D tetrahedral network makes it the hardest natural material, while graphite's flat hexagonal sheets are held together only by weak forces, letting them slide past each other (used as a lubricant and in pencils).
Concept context
Covers the Boron family (Group 13: B, Al) and the Carbon family (Group 14: C, Si, Ge, Sn, Pb). Key topics include Lewis acid behaviour of BF₃, borax bead test, silicates, silicones, allotropes of carbon, and trends in properties down the group.