Which of the following molecules is called buckministerfullerene?

C₉₀ C₆₀ C₇₀ C₁₂₀

9 How does graphite act as a lubricant? 10 Name the hardest natural substance known. 12 Give the name and structural formulae of an alkyl group. 13 Write the electron-dot structure for:

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