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Question 1. Which of the following transition metal oxides is paramagnetic? (a) TiO (b) VO (c) Cu2O (d) Mn2O3 Answer Answer: (b) VO Question 2. Which of the following transition metal oxides is not an insulator? (a) MnO (b) NiO (c) VO (d) Mn2O3 Answer Answer: (c) VO Question 3. Coordination number in ccp and hep arrangements of metal atoms are respectively. (a) 6, 6 (b) 12, 6 (c) 8, 6 (d) 12, 12 Answer Answer: (d) 12, 12 Question 4. An example of body centered cube is (a) Sodium (b) Magnesium (c) Zinc (d) Copper Answer Answer: (a) Sodium Question 5 Fe3O4 is ferrimagnetic at room temperature but at 850 K it becomes (a) Diamagnetic (b) Ferromagnetic (c) Non-magnetic (d) Paramagnetic Answer Answer: (d) Paramagnetic Question 6. Which of the following is not an example of 13-15 compounds, (a) InSb (b) GaAs (c) CdSe (d) Alp Answer Answer: (c) CdSe Question 7. For tetrahedral coordination, the radius ration (r+/r ) should be (a) 0.155-0.225

From our earlier studies, we know that liquids and gases are called  fluids  because of their ability to flow. The fluidity in both of these states is due to the fact that the molecules are free to move about. On the contrary, the constituent particles in solids have fixed positions and can only oscillate about their mean positions. This explains the rigidity in solids. These properties depend upon the nature of constituent particles and the binding forces operating between them. The correlation between structure and properties helps in the discovery of new solid materials with desired properties. For example, carbon nanotubes are new materials that have potential to provide material that are tougher than steel, lighter than aluminium and have more conductive property than copper. Such materials may play an expanding role in future development of science and society. Some other materials which are expected to play an important role in future are high temperature superconductors, magnet