Why does it take a lot of energy to melt sodium chloride?
It is a giant ionic structure with strong electrostatic forces which means more energy is needed to break up these forces
1 of 14
Why are compounds such as methane and ammonia, gases at room temperature?
They are made of small molecules
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Polymers made from different monomers have different properties. Explain why.
Different monomers change the structure of the polymer chains because polymer chains are different shapes and sizes
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Some dental braces are made from shape memory alloys. What is meant by a shape memory alloy?
A substance which is a mixture of metals that can be meant/ deformed and changes back into its original shape when heated
4 of 14
Explain why diamonds are very hard.
Every carbon atom is covalently bonded to 4 other carbon atoms in its structure.
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Why do ionic compounds need to be molten or in solution to conduct electricity?
The ions cannot move in the solid, but become free to move in the molten liquid/ solution.
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Explain why a block of copper can be hammered into a sheet.
The atoms are in layers and these layers can slide over each other into the new shape.
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Silver nanoparticles are used in socks to prevent bad smells. How are silver nanoparticles different to regular silver particles?
They are very small and have a greater surface area.
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Silver nanoparticles are used in socks to prevent bad smells. Suggest why the manufacturers used nanoparticles instead of regular silver particles.
They are more effective and cheaper.
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Explain why thermosetting polymers are used to make handles for cooking pans.
They do not soften when they get hot. Good insulators of hot. Can be molded into shapes then become rigid when cooled.
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Explain how the atoms in a metal are bonded together.
The outer electrons delocalise leaving a lattice of positive ions. The delocalised electrons strongly attract the positive ions and hold them in position.
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Why can graphite conduct electricity?
The delocalised electrons in graphite carries the charge.
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Explain what is meant by intermolecular forces.
The forces between molecules.
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What is a fullerene?
Forms of carbon, with large molecules with hexagon cage like structures.
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Other cards in this set
Card 2
Front
Why are compounds such as methane and ammonia, gases at room temperature?
Back
They are made of small molecules
Card 3
Front
Polymers made from different monomers have different properties. Explain why.
Back
Card 4
Front
Some dental braces are made from shape memory alloys. What is meant by a shape memory alloy?
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