Solid State - Q and Answer

Solid State (25 Marks):

1. Name one solid which show both Frenkel defect & Schottky defect.

2. In a close packing of N spheres how many (i) tetrahedral (ii) octahedral sites are present?

3. Describe energy gap in conductors & semiconductors band theory.

4. What type of defect is produced when NaCl is doped with MgCl2?

5. Define ‘F’ Center.

6. What is the two dimensional coordination number of a molecule in square close packed layer & hexagonal close packing?

7. Describe metal excess deficiency.

8. Describe the p-type semiconductors.

9. Ionic solids, which have anionic vacancies due to metal excess defect, develop. Explain with the help of a suitable example?.

10. ZnO is white but it turns yellow on heating, explain.

11. An element with molar mass 7 × 10-2 kg mol-1 forms a cubic unit cell with edge length 405 pm. If its density is 2.7 × 103 kg m−3, what is the nature of the cubic unit  cell?                        

12. Explain the following with suitable examples:

i. Ferromagnetism.
ii. Paramagnetism.       
iii. Ferrimagnetism.
iv. Antiferromagnetism.               
iv. 12-16 and 13-15 group compounds.                                                      5