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20 Cards in this Set
- Front
- Back
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Which solids do not conduct electricity? |
Ionic solids and covalent-network solids because 1. Valence electrons are confined in anions in ionic solids and 2. No mobile electrons |
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Which covalent-network solid conducts electricity? |
Graphite since it has delocalized double bonds |
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Brittle and high melting/boiling point solid |
Ionic solid |
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Malleable and held together by delocalized sea of shared valence electrons= __ solid |
Metallic solids (Cu, Fe) |
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Molecular solids: Softness High or low melting points Examples |
Soft Low melting point Ar, H20, CO2 |
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Most substances that are gases of liquid at room temperature form _____ solids at low temperatures. |
Molecular |
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Alloy |
Material containing more than one element and has characteristic properties of metals |
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Properties of heterogeneous alloy depend on |
Composition and the way in which the solid is formed by the cooling of the mixture |
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14 karat gold is how much mass percent |
14÷24)*100= 58% gold |
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What types of gold are intermetallic compounds? |
Blue (indium) and purple (aluminum) Both brittle |
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Electron-sea model |
Electrons are mobile and uniformly distributed. |
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Mobility of electrons in metals accounts for |
High thermal conductivity of metals |
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Plastic |
Materials that can be formed into various shapes |
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Thermoplastic |
Materials that can be reshaped, like polyethylene |
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Thermosetting plastic |
Material that cannot be reshaped, is irreversibly changed |
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Elastomer |
Material that exhibits rubbery or plastic behavior |
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Isoprene |
Monomer that is polymerized to make natural rubber (NOT a nano material) |
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Graphene |
Low electrical conductivity and zero energy gap) |
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3 things electron sea model accounts for |
1. Electrical conductivity, current forces electrons to flow toward the positive end of the wire 2. High thermal conductivity, temperature gradient moves electrons 3. Malleability, metal atoms form many bonds with neighbors and electrons can be redistributed |
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Why are polymers flexible |
Atoms are free to rotate around the carbon carbon single bonds |
