闪卡自测
What is a nanoparticle?
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闪卡 1
问题
What is a nanoparticle?
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答案
A nanoparticle is a particle between 1 and 100 nanometres in size, usually containing only a few hundred atoms.
闪卡 2
问题
Calculate the surface area in cm2.
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答案
The surface area is: 3 x 3 x 6 = 54 cm2
闪卡 3
问题
Calculate the volume in cm3.
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答案
The surface area is: 3 x 3 x 3 = 27 cm3
闪卡 4
问题
A particle has a surface area of 24 cm2 and a volume of 8 cm3. What is the surface area to volume ratio?
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答案
The surface area to volume ratio in 3:1.
闪卡 5
问题
True or False? Nanoparticles are larger than fine particles.
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答案
False. Nanoparticles are much smaller than fine particles, which have diameters between 100 and 2500 nm.
闪卡 6
问题
How are nanoparticles of silver used in medical applications?
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答案
Nanoparticles of silver are sprayed onto the fibers of medical clothing and surgical masks to provide antibacterial properties while maintaining flexibility.
闪卡 7
问题
How are fullerenes used in medicine?
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答案
Fullerenes are used in medicine and drug design as they are more easily absorbed than other particles and can deliver drugs to target areas more effectively.
闪卡 8
问题
What is a potential risk of nanoparticles in medical applications?
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答案
A potential risk of nanoparticles in medical applications could be:
闪卡 9
问题
True or False? As particles decrease in size, their surface area decreases in relation to their volume.
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答案
False. As particles decrease in size, their surface area increases in relation to their volume.
闪卡 10
问题
True or False? The main industrial application of nanoparticles is in catalysis due to their high surface area to volume ratios.
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答案
True. The main industrial application of nanoparticles is in catalysis due to their high surface area to volume ratios.
闪卡 11
问题
Define composite material
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答案
A composite material is made from two components: reinforcement and matrix, where the matrix binds the reinforcement together.
闪卡 12
问题
True or False? Clay ceramics are soft materials that do not resist compressive forces.
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答案
False. Clay ceramics are hardened materials that resist compressive forces.
闪卡 13
问题
What are the main characteristics of polymers?
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答案
The main characteristics of polymers are
闪卡 14
问题
Why are metals good conductors of electricity?
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答案
Metals are good conductors of electricity due to delocalise electrons being able to flow and carry a current.
闪卡 15
问题
Give an example of a composite material.
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答案
An example of a composite material could be:
闪卡 16
问题
True or False? Polymers are good conductors of heat and electricity.
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答案
False. Polymers are poor conductors of heat and electricity, making them good thermal and electrical insulators.
闪卡 17
问题
What is an alloy?
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答案
An alloy is a mixture of a metal with other elements, which has different properties to the elements it contains.
闪卡 18
问题
Why is aluminium used in the construction of airplanes?
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答案
Aluminium is used in the construction of airplanes because it is a very strong metal but also very light, giving it a high strength-to-weight ratio.
闪卡 19
问题
What are the advantages of carbon-fibre composites?
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答案
Carbon-fibre composites are extremely strong and low weight, making them useful in aviation, aeronautics, and professional racing bicycles.
闪卡 20
问题
Why are polymers useful for insulating electrical wiring?
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答案
Polymers are useful for insulating electrical wiring because they prevent electric shocks and overheating due to their poor conductivity of heat and electricity.