C6 Allotropes Of Carbon Flashcards
Nanotubes
Type of fullerene and are molecular-scale tubes of carbon arranged similarly to the layers in graphite.
Carbon nanotubes have a very high melting point, as each carbon atom is joined to three other carbon atoms by strong covalent bonds. This also leaves each carbon atom with a spare electron, which forms a sea of delocalised electrons within the tube, meaning nanotubes can conduct electricity.
Allotropes of carbon
Diamond, graphite and fullerenes (substances that include nanotubes and ‘buckyballs’, such as buckminsterfullerene) are three allotropes of pure carbon.
In all three allotropes, the carbon atoms are joined by strong covalent bonds, but in such different arrangements that the properties of the allotropes are very different.
What is diamond and what does it look like?
A diamond is one giant molecule of carbon atoms. Diamonds are colourless and transparent. They sparkle and reflect light, which is why they are described as lustrous. These properties make them desirable in items of jewellery.
Is diamond hard or soft?
Diamond is extremely hard and has a high melting point. For this reason, it is very useful in cutting tools. The cutting edges of discs used to cut bricks and concrete are tipped with diamonds. Heavy-duty drill bits – such as those used in the oil exploration industry to drill through rocks – are made with diamonds so that they stay sharp for longer.
Is diamond a conductor - explain its bonding?
Diamond is insoluble in water. It does not conduct electricity. Every atom in a diamond is bonded to its neighbours by four strong covalent bonds, leaving no free electrons and no ions. This explains why diamond does not conduct electricity.
The bonding also explains the hardness of diamond and its high melting point. Significant quantities of energy would be needed to separate atoms so strongly bonded together.
