Give the name and structural formulae of an alkyl group.

10 Name the hardest natural substance known. 11 Which of the following molecules is called buckministerfullerene?

C₉₀ C₆₀ C₇₀ C₁₂₀

13 Write the electron-dot structure for:

(i) ethane, (ii) ethane, and (iii) ethyne.

14 Give the IUPAC name of the following compound: C₂H₆