10. Why are metals good conductors of electricity?
(1) They havelarge numbers of charge carriers(2)thecharge carriershavehighmobility.
11. Which sort of polarization can occur in all materials, regardless of the type of bonding in the solid?
13. How do paramagnetic, diamagnetic,antiferromagneti，ferromagnetic and ferrimagnetic materials response to external magnetic field?
或The magnitude ofΔG is the driving force for a phase change.
9. What is the physical meaning of Young’s modulus?
It measures the inter-atomic bonding force and, therefore, the stiffness of the material.
Metal or composite materials.
3.Whichtype of bonding is responsible for the condensation of noble gases at low temperatures?
van der Waals bonding
4. How many atoms are there in the structure of a face-centered cubic unit cell?
The structure of the metal resulting from innovative processing methods provided new combinations of properties that offered significant advantage to those who developed the technology.
7. Why does three-phase equilibrium occur at a fixed temperature and pressure in a single-component system?
The phase rule tells us that F=0, andthere is no freedom to change variables.
2. Which class of engineering materials should be used when a combination of high strength and resistance to brittle fracture is required in some applications?
本科课程考试试题参考答案及评分标准
开课单位：化学化工学院学生所在学院：化学化工学院（2006～2007年第1学期）
课程编号
02832480
学分/总学时
2 /32
课程名称
工程材料科学与设计
课程类别
□公共课□专业课
专业/年级
材料化学（2003级）
修读方式
□必修选修
出题教师
苏海全
是否主干基础课
否
考试方式
□闭卷□开卷
Electronic polarization.
12. When light encounters a medium of different refractive index, what properties will be changed?
Not only do the speed and wavelength change abruptly,but so also does the direction of the light.
6. Amorphous polymers and oxide glasses are transparency to visible light, but polycrystalline ceramics and semicrystalline polymers are opaque. Why?
Because inpolycrystalline ceramics and semicrystalline polymersthere aregrain boundarieswhichscatter light.
4Байду номын сангаас
5. Why do not isolated single vacancies occur in ionic crystals?
Becausethe removal of a single ion would result in an electrical charge imbalance in the crystal.
注：1.出题教师负责制订课程考试试题参考答案及评分标准（列出答案要点即可），不够可另附页。
2.试题参考答案及评分标准与试题一并交学院。
3.试卷评完后，此表随同试卷交学院，由学院妥善保存。
8. What isthe driving force for a phase change?
A phase changedepends solely on the change in free energy for the reaction.
一、Please Answer the Following Questions（4Points for Each，Totally 60 Points）
1. How the relationship between structure, properties, and processing was linked by the example of the development of theDamascussword?