1. For the principal quantum number n = 4 the shell designation is _______. There are _____ subshells named ______________ . The maximum number of electrons in the shell is _______. 2. The atomic number for element oxygen is ___________; its electron configuration is _______________________________________________. The valence electrons for this element are _________________________. 3. For element Li, what are the 4 quantum numbers to characterize the electrons which participate in the bonding between Li and Cl in LiCl? 4. How does the radius of a group 1 element changes if it is involved in an ionic bond? Explain why !

5. Which types of chemical bonding (pure covalent, covalent-ionic, pure ionic or metallic) will be formed in between the following elements?

elements	type of chemical bond
silicon and silicon
iron and copper
oxygen and nitrogen
lithium and fluor

6. What is the FCC crystal structure? ____________________________________________________________________. For the FCC structure, a total of ______ atoms can be assigned to a given unit cell; the coordination number is ________ and the APF is _________. 7. How does the number of defects in crystal lattices change with temperature? The number of Schottky defects _________________ with decreasing temperature. The number of Frenkel defects __________________ with increasing temperature. The number of impurities ______________________ with decreasing temperature.

8. A negative charged Gallium (charge: -e0) is placed on a Si lattice site in silicon. Give the Krger-Vink notation of this type of defect: 9. Which types of 3-dimensional bulk or volume defects can occur in an amorphous material. Name 2 of them

11. To measure the electric conductivity of a material, which is expected to have a high electric conductivity value, the _____________________________________ should be applied to ensure a high accuracy / low measurement error.

12. What type of conductivity do the following materials exhibit? Give an equation f(T) for the temperature dependency (T) f(T). Nickel silicon SiO2

13. In insulators and semiconductors the Fermi-energy is located _________________

14. According to the Drude-modell, the electrons are _____________________ by the electrical field. During the transport through the crystalline lattice, the electrons interact with ____________________. In the time between two scattering events the electrons are __________________________ according to classical mechanics. The mean free path length is in the order of ___________________________. 15. If a metal is deformed, the electrical resistivity of the metal becomes ______________, whereas the temperature coefficient of the resistivity_______________________.

16. At ___________________ all energy states above the Fermi energy Ef are empty 17. Name 3 selection criteria for metals to be applied as contact materials 18. In Al doped silicon the number of mobile holes in the valence band ________________ than the number of mobile electrons in the conduction band. 19. PTC-materials exhibit a positive temperature coefficient of the resistivity only around their _________________________. At much lower or much higher temperatures they show a ________________________ temperature coefficient of the resistivity

20.Name 3 applications for PTCs __________________________. __________________________. __________________________.

21. AT high temperatures (> 500 C) yttria doped zirconia is a ____________________ conductor. The ionic conductivity increases with increasing Y2O3-content up to a maximum value at a dopant concentration of _______ mol% Y2O3. 22. A directed movement of mobile charge carriers (current density) is caused by __________________________ and / or _________________________. 23. Blocking electrodes are applied in __________________________. 24. When an electric field is present, the polarizability of dielectric materials can be represented as: in PVC: ______________________________________________ in diamond: ______________________________________________. in MgO: ______________________________________________. 25. With increasing frequency, the dielectric polarization mechanisms drop out. In case of __________________________ and ____________________________ the mechanism is called relaxation, whereas in case of ____________________________ and ____________________________ the mechanism is called resonance. 26. In ferroelectric materials a spontaneous polarization occurs at temperatures below the ____________________________. 180- and 90-domains are formed to minimize the ___________________________ and ___________________________ energy. 27. The piezoelectric effect occurs in polycrystalline materials which exhibit ___ _______________________ at T < TC. The statistically distributed domains have to been aligned by an _____________________________________________. 28. Magnetic dipoles in a paramagnetic material are aligned _______________ __________________________ of an applied external magnetic field. 29. Which types of magnetic dipoles exist in the following materials? titanium (Ti): ____________________ silver (Ag): ____________________ nickel (Ni) at T < TC: ____________________ oxygen (O2): ____________________ 30. Ferrite cores exhibit low __________________________ because of the low ___ _______________________ of the ferrites.