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Carbon nanotubes are a new material - OCR Gateway - GCSE Chemistry: Combined Science - Question 11 - 2018 - Paper 1
Question 11
Carbon nanotubes are a new material. The diagrams show how a graphene sheet can form a nanotube. (a) Nanotubes are more than 100 times stronger than iron. Explain ... show full transcript
Worked Solution & Example Answer:Carbon nanotubes are a new material - OCR Gateway - GCSE Chemistry: Combined Science - Question 11 - 2018 - Paper 1
Step 1
Explain why nanotubes are so strong. Use ideas about bonding.
Answer
Nanotubes possess exceptional strength due to their unique structure and bonding characteristics. They are made up of carbon atoms that are covalently bonded in a hexagonal lattice structure, similar to graphene.
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Strong Covalent Bonds: The covalent bonds between carbon atoms in the nanotube are extremely strong, requiring significant energy to break.
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Extensive Network: Each carbon atom forms strong bonds with three other carbon atoms, creating a highly interconnected network. This structure distributes stress evenly, which further enhances strength.
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Giant Covalent Structure: The overall tetrahedral arrangement of bonds allows for the formation of a giant covalent structure, contributing to its remarkable mechanical properties.
Step 2
Explain why carbon nanotubes conduct electricity.
Answer
Carbon nanotubes are capable of conducting electricity due to their unique electronic properties.
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Delocalized Electrons: The carbon atoms in the nanotubes have p-orbitals that overlap, creating delocalized π electrons. These electrons can move freely along the length of the nanotube, allowing for electrical conductivity.
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Structure: The cylindrical structure of carbon nanotubes enables the efficient movement of these delocalized electrons, which is a key aspect of their conductive properties. In this way, carbon nanotubes can behave similarly to metals in terms of electrical conduction.