Can you please tell me which ones are true and which ones are false ? a- Amorphous and semi-crystalline polymers both become brittle at lower temperatures b- Localized heating at high frequencies results in polymer softening causing polymer fatigue c- The elastic modulus of semi-crystalline polymers rises as chain entanglement decreases d-Polymers are similar to metals in that they can also exhibit both ductile and brittle fracture e- Phonons scatter from dislocations in metals, reducing heat transfer efficiency f- The maximum phonon energy is limited by the interatomic lattice spacing g- Phonons arise from excitation of electrons to higher energy levels in an atom h- Increased temperature in many ceramics up to around 1000 °C leads to a decrease in thermal conductivity
Can you please tell me which ones are true and which ones are false ?
a- Amorphous and semi-crystalline polymers both become brittle at lower temperatures
b- Localized heating at high frequencies results in polymer softening causing polymer fatigue
c- The elastic modulus of semi-crystalline polymers rises as chain entanglement decreases
d-Polymers are similar to metals in that they can also exhibit both ductile and brittle fracture
e- Phonons scatter from dislocations in metals, reducing heat transfer efficiency
f- The maximum phonon energy is limited by the interatomic lattice spacing
g- Phonons arise from excitation of electrons to higher energy levels in an atom
h- Increased temperature in many ceramics up to around 1000 °C leads to a decrease in thermal conductivity
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