1.1. In 1985 the fullerenes were discovered. They are solid forms of the element carbon. The structure of the C₆₀ fullerene is given below.

i) In the C₆₀ fullerene, how many other carbon atoms is each carbon atom bonded to?

[1]

ii) Another fullerene has a relative molecular mass of 840.

How many carbon atoms are there in one molecule of this fullerene?

[1]

1.2. Fullerenes are soluble in liquid hydrocarbons such as octane. The other solid forms of carbon are insoluble.

Describe how you could obtain crystals of fullerenes from soot which is a mixture of fullerenes and other solid forms of carbon.

1.3. A mixture of a fullerene and potassium is an excellent conductor of electricity.

i) Which other form of solid carbon is a good conductor of electricity?

[1]

ii) Explain why metals, such as potassium, are good conductors of electricity.

[2]

iii) The mixture of fullerene and potassium has to be stored out of contact with air. There are substances in unpolluted air which will react with potassium.

Name two potassium compounds which could be formed when potassium is exposed to air.

[2]