Question

Which of the following are common characteristics of thermoset polymers?

Group of answer choices

None of the these.

Linear or slightly branched long chain molecules.

Soften on heating and harden on cooling.

Heavily networked or cross linked structures.

Which of the following statements is a TRUE statement?

Group of answer choices

Higher molecular weight of a polymer will always have superior properties.

Crystallization is not affected by the molecular weight of the polymer.

Elastomers have very long chains with a high degree of cross linking.

Crystalline polymers are optically transparent.

The resistance of a metal, R, is defined by the equation of R = ρ l A where A is cross-sectional area, l is length, and ρ is resistivity. How would you categorize resistance?

Resistance is a __________.

Group of answer choices

Process

Property

Structure

Performance

Other

The addition of a boron (B) impurity to otherwise pure silicon (Si) will:

(Pick all correct answers)

Group of answer choices

Decrease conductivity due to additional scattering of electrons due to the impurity

Create an additional allowable energy level inside the band-gap called an acceptor level

Create an extrinsic semiconductor with the majority charge carrier being a hole instead of an electron

The casting process is preferred for processing brittle metals.

Group of answer choices

True

False

Normalizing process transforms deformed large grains into smaller grains.

Group of answer choices

True

False

Titanium alloys have higher strength and density than steel alloys.

Group of answer choices

True

False

MgO and FeO have an NaCl structure.

Group of answer choices

True

False

Answer 1

Solution is attached in the image posted below.

Hope it helps you.

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As per guidelines first four sub-parts are to be solved.