³ÉÈË¿ìÊÖ

Available for over a year

In this episode, Dr Sunayana Bhargava and Tulela Pea look at the structure and properties of different allotropes of carbon including diamond, graphite, graphene and fullerenes. Suitable for: AQA, Edexcel, OCR. For more information on allotropes of carbon, check out the ³ÉÈË¿ìÊÖ Bitesize website: /bitesize/guides/zspxdxs/revision/2 Key learning objectives discussed in this episode include: - In diamond, each carbon atom forms four covalent bonds with other carbon atoms in a giant covalent structure, so diamond is very hard, has a very high melting point and does not conduct electricity. - In graphite, each carbon atom forms three covalent bonds with three other carbon atoms, forming layers of hexagonal rings which have no covalent bonds between the layers. - In graphite, one electron from each carbon atom is delocalised. - Students should know that graphite is similar to metals in that it has delocalised electrons. - Graphene is a single layer of graphite and has properties that make it useful in electronics and composites. - Fullerenes are molecules of carbon atoms with hollow shapes. The structure of fullerenes is based on hexagonal rings of carbon atoms but they may also contain rings with five or seven carbon atoms. The first fullerene to be discovered was Buckminsterfullerene (C60) which has a spherical shape. - Carbon nanotubes are cylindrical fullerenes with very high length to diameter ratios. Their properties make them useful for nanotechnology, electronics and materials.