1 Marks1. How many groups are there in p-block? [1]2. What is ‘inert pair effect’? [1]3. How does metallic and non-metallic character vary in a group? [1]4. Why do third – period elements expand their covalence above four? [1]5. Why do heaver elements form π – bonds? [1]6. Where does metalloids and non – metals exist? [1]7. How does boron interact with Na OH? [1]8. Give two examples of electron deficient molecules. [1]9. Arrange the following halides of boron in the increasing order of acidic

character: BF3, BCl3, BBr3, BI3.[1]10. Boron is unable to form BF6

3- ion why? [1]11. Why is boron metalloid? [1]12. Why do boron have unusual high melting point? [1]13. Why does BF3 act as Lewis acids? [1]14. What is the electronic configuration of Group -14 elements? [1]15. Name the metalloid found in Group 14 element? [1]16. Which of the following reacts with water and aqueous solution becomes acidic:

SiCl4 or CCl4?[1]17. Why CCl4 behaves as an electron precise molecule? [1]18. Why is lead unaffected by water? [1]19. What is the common name of recently developed allotrope of carbon i.e. C60

molecule?[1]20. How are fullerenes obtained? [1]21. Diamond is the hardest substance known. Why? [1]22. What is water gas? [1]23. Silicon dioxide is treated with hydrogen fluoride. Explain? [1]24. What are silicones? [1 ]25. What is dry ice? [1 ]26. What are silicates? [1 ]27. Write the resonance structures of carbon dioxide. [1]28. What is silica-gel used as? [1]29.

2 Marks1. Why the elements of group 13 are called p-block elements? [2]2. The elements B, Al, Ca, In and Tl are placed in the same group of the periodic

table. Give reason.[2]

Chapter No. Subject Topic Class Batch1 Chemistry The P-Block Elements 11 Nucleus

3. Aluminium forms [AlF6 ]3- [BF6 ]3- in not formed why? [2]4. How do Boron and Aluminium interact with Na OH? [2]5. The atomic radius of Ca is less than that of Al. Why? [2]6. C and S are always tetravalent but Ge, Sn And Pb show divalency. Why? [2]7. [SiF6]2- is lead known whereas [ SiCl6]2- not. Give reason. [2]8. PbI4 does not exist. Why? [2]9. Some halides of group 14 elements form complexes of the type [ Mx6]2-. Give reason. [2]10. Why is carbon different from other member of the group? [2]11. Why does the covalence of carbon not expand beyond four? [2]12. Why does carbon show different allotropic forms? [2]13. Silicon has no allotropic form analogous to graphite. Why? [2]14. Why does graphite conduct electricity? [2]15. Graphite is used as lubricant. Give reason. [2]16. How are silicones manufactured? [2]17. Why does CO2 have a linear shape with no dipole moment [2]18.

3 Marks1. Why carbon does not form ionic compounds? [3]2. Why does the heavier elements do not form pπ – pπ multiple bond as carbon

do?[3]3. Why is CO considered poisonous ? [3]4.

5 Marks