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Question 1
Diamond and graphite both contain the same element. |
a) | What is the name of this element?
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b) | Graphite is softer than diamond. Explain why.
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c) | Graphite conducts electricity, but diamond does not. Explain why.
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Question 2
Different forms of carbon have different uses in the modern world. The image below shows the structure of diamond and graphite. |
a) | Pencils are used for writing because graphite rubs off the pencil onto the paper. Explain why graphite is used in pencils. Include information on the bonding and structure in graphite.
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b) | Abrasives are hard materials used to wear away the surface of softer materials. Explain why diamonds are used as abrasives. Include information on the structure and bonding in diamonds.
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c) | A graphene sheet is a single layer of graphite. Graphene conducts electricity and can be used in loudspeakers and touchscreens. |
c) i) | Use the image above and your own knowledge to explain why graphene is strong.
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c) ii) | Use the image above and your own knowledge to explain why graphene can conduct electricity.
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d) | How many other atoms does each atom in graphene bond to? A one B two C three D four
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e) | Suggest why a block of graphite, which has a large number of graphene sheets, could not be used for a touchscreen.
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Question 3
Carbon nanotubes have applications in many fields. The properties of carbon nanotubes make them ideal for the improvement of sports equipment, body armour and vehicles. The image below shows the structure of a carbon nanotube. |
a) | What does the term ‘nano’ tell you about the carbon nanotubes?
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b) | Carbon nanotubes are structurally similar to graphite. How many other carbon atoms is each carbon atom joined to in carbon nanotubes and in graphite? A one B two C three D four
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c) | What type of bond holds the atoms together in carbon nanotubes?
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d) | Explain why carbon nanotubes are very strong.
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e) | Explain why carbon nanotubes conduct electricity.
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Question 4
Diamond and graphite are both made up of carbon atoms. The image below shows the structures of diamond and graphite. |
a) | Diamond and graphite have very different properties and uses in everyday life. The different properties of carbon and diamond arise from their different structures. |
a) i) | What property of diamond makes it suitable for use on the cutting end of a drill bit?
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a) ii) | Explain why diamond has this property.
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b) | Graphite is a good lubricant because it is slippery. Use the diagram to explain why graphite is slippery.
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Question 5
Diamond is composed of carbon atoms. The arrangement of the carbon atoms in diamond determines its properties. |
a) | The diagram shows the outer electron shells of five carbon atoms in the giant lattice of diamond. Carbon atom C forms bonds with each of the carbon atoms 1, 2, 3 and 4. Draw the positions of all the electrons in the outer shells of each of carbon atoms C, 1, 2, 3 and 4.
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b) | Explain why diamond has a high melting point.
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Question 6
Diamond nanoparticles can be found in some meteorites. |
a) | How many atoms do nanoparticles contain?
A a few dozen B a few hundred C a few thousand D a few million
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b) | Diamond nanoparticles are made from which type of atom? A carbon B nitrogen C hydrogen D iron
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c) | Meteorites get very hot when they pass through the Earth’s atmosphere, but the diamonds do not melt. Explain why.
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d) | Describe the structure and bonding in diamond.
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Question 7
Explain why graphite is:
Your answer should refer to details of graphite's structure.
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Question 8
Graphite and fullerenes are forms of carbon. The image below shows a model of a Buckminsterfullerene molecule. |
a) | A lubricant is a substance that allows materials to move over each other easily. Suggest why Buckminsterfullerene is a good lubricant.
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b) | Buckminsterfullerene can be used in medicine to move drugs around the body. Suggest two reasons why Buckminsterfullerene is suitable for this use.
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c) | Give one other use of a fullerene such as Buckminsterfullerene.
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Question 9
Nanoparticles have many uses. |
a) | What are nanoparticles?
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b) | Coarse particles, fine particles, and nanoparticles, are all small particles. Which is the largest particle? A coarse particle B fine particle C nanoparticle
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c) | Silver can form cubic nanocrystals. A silver nanocrystal is a cube, with a side length of 2 nm. Calculate the surface area to volume ratio of the nanocrystal.
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d) | Silver has been used for hundreds of years to treat burns and wounds. Nowadays, silver nanoparticles are used in bandages and plasters. Suggest why it is cheaper to use nanoparticles of silver rather than coarse particles of silver.
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e) | Some scientists are concerned about the possible risks of using nanoparticles. Give one possible risk of using nanoparticles.
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Question 10
Nanoparticles of cobalt oxide can be used as catalysts in the production of hydrogen from water. |
a) | Which of these is another use of nanoparticles? A in the extraction of iron B in the test for oxygen C in suncreams
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b) | How does the size of a nanoparticle compare with the size of an atom?
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c) | Complete the sentences below. Compared with cobalt oxide powder, the surface area to volume ratio of cobalt oxide nanoparticles is . This means that the mass of a nanoparticle catalyst needed to have the same effect as the same catalyst made of normal sized particles is . The use of a nanoparticle catalyst increases the frequency of collisions, increasing the rate of reaction. high low
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Question 11
Mineral sun creams use nanoparticles, usually of titanium oxide and zinc oxide. The nanoparticles in the sun cream are very good at absorbing ultraviolet radiation, protecting the skin from damage. Due to the size of the nanoparticles, mineral sun creams spread easily, cover better and are transparent on the skin, unlike chemical sun creams which are white. Mineral sun creams can save customers money because less product needs to be used. Normal-sized particles of titanium oxide and zinc oxide are safe to put on the skin. Nanoparticles, however, can pass through the skin and travel around the body more easily than normal-sized particles. Some scientists believe that nanoparticles might be toxic to some types of body cells. |
a) | An atom has a radius of 1 × 10−10 m. A spherical nanoparticle has a radius of 1 × 10−8 m. How many times larger is the radius of the nanoparticle than the radius of the atom?
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b) | Explain why nanoparticles pass through the skin and travel around the body more easily than normal-sized particles of titanium oxide.
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c) | Suggest two reasons why it may be necessary to test mineral sun creams further.
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d) | Suggest two reasons why companies that make mineral sun creams may be reluctant to carry out further tests.
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