Page 1 of 3. 1. CLASSIFICATION OF ELEMENTS AND PERIODIC TABLE. MODEL QUESTIONS. 1.Name the scientist who classified elem
1
CLASSIFICATION OF ELEMENTS AND PERIODIC TABLE MODEL QUESTIONS 1.Name the scientist who classified elements into metals and non metals. 2. Lavoisier was one of the scientists who attempted to classify elements. On what basis did he classify the elements. What was the major shortcoming of his classification? 3. Name the scientist who put forward atomic theory. What was the main idea of this theory? 4. Dobereiner, a German scientist classified elements having similar properties into the groups of three. What was named this groups? 5. Who did classify the elements into triads? 6. What ido you mean by triads? 7. Dobereiner grouped the elements of similar properties as TRIADS. Give one more feature of the elements belong to a TRIAD. 8. Give a few examples for Dobereiner's TRIADS. 9. What was the demerit of Dobereiner's classification? 10. Who put forward the idea of "Telluric Helix"? 11. Who did propose the law of Octaves? 12. Give a brief account on the law of Octaves . 13. What was shortcoming of New Lands law of Octaves? 14. Julius Lothar Meyer had arrived the conclusion that atomic mass is the fundamental property of elements. How did he arrived in this conclusion? 15. Who did propose the periodic law of elements? State the law. 16. About 118 elements were discovered so far. How many elements were known to Mendeleev in 1869 when he classified the elements? 17. Give a brief note on Mendeleev's classification of elements. 18. Mendeleev arranged the then known elements in periods and groups. How many periods and groups were there in his periodic table? 19. Where did Mendeleev included the elements of similar properties in his periodic table? 20. In spite of many advantages, Mendeleev's periodic table had some limitations also. Point out two limitations with examples. 21. List out the major advantages of Mendeleev's periodic table. 22. The element's classification of Mendeleev leads to the discovery of new elements. Name the elements predicted by him. What were named these elements after the discovery? 23. What was the shortcoming of the Mendeleev's periodic table in respect of the arrangements of isotopes? 24.Name the scientist who designed modern periodic table. What is the major difference of modern periodic table to that of Mendeleev's. 25. Moseley prepared the modern periodic table based on the idea that the properties of elements depended on the atomic mass. Which experimental result led him to this conclusion? 26. Who did propose modern periodic law? State the law. 27.See the modern periodic table and answer the following questions. a. How many periods are there in it? b. Number of groups? c. Which is the period that includes least number of elements? How many elements are there in it and which are they? d. The number of elements in 2nd and 3rd periods are equal. How many elements are in each period? 28. In the modern periodic table, elements of similar properties are grouped as families. a. How many families are there in modern periodic table? b. Name the family which contains most number of elements. c. Which are the groups that included in this family? 29.a.Which are elements known as representative elements? b. Why are they called so? 30. Name two elements existing in liquid state at atmospheric temperature. 31. a. The elements belong to which group is called noble elements? b. What are the features of these elements.? 32. Give a few examples for noble gases. Why these element do not usually take part in chemical reaction? 33. a. What is known as transition elements? b. Give a few examples for transition elements. c. Write down some features of these elements. 34. Give a brief account on inner transition elements. 35. What are lanthanoides? It is also known in another name. What is it? 36. What are Actinoides? www.shenischool.in To Join our whatsapp Group?Telegram SMS your Name to 9447490316
2 37. Explain with example why the elements in the same group exhibit similarity in chemical properties? 38. What is the relation between group of an element and number of electrons in the outermost shell of its atom? 39. What is the relation between the number of shells in an atom and its period in the periodic table. 40. How does size of an atom change in a group of periodic table? 41.How does size of an atom change in a period of periodic table? Give reason for this change in size. 42. What is ionisation energy? What are the factors influencing ionisation energy of an atom? 43. What is the relation between size of an atom and its ionisation energy? 44. How does ionisation energy change while moving from top to bottom in a group? 45. How does ionisation energy change in a period? 46.Electro negativity is the ability of an atom to attract the bonded electrons that took part in covalent bonding. How does electro negativity change in period and group? 47. All metals are electro positive. What is electro positive elements? 48. What do you mean by electronegative elements? 49. How do the metallic and non metallic property change in group and period? 50.What is the relation between ionisation energy and metallic property? 51. What is metalloids? 52. How do the size,metallic property, non metallic property, ionisation energy and electro negativity of atoms change in group and period. 53. Matters relating to the classification of elements are given in the table below. Complete the table. Contribution/discovery Scientist Triads
..............
Atomic mass – volume graph
..............
Tell-uric Helix
..............
..............
John Dalton
Classification as metals& non metals
..............
Modern periodic table .............. 54. Complete the following statements. a. Elements showing similar properties are included in .................... (Group/Period) b. Electro negativity of atoms ...... as we move from left to right in a period. ( increases/decreases) c. The metallic property of elements ........ as we move from top to bottom in a group. (increases /decreases) d. As we move from left to right in a period the metallic property ........ ( increases/decreases) e. The size of atom ..... as we move from top to bottom in a group. ( increases/decreases) 55. Check the correctness of the following statements and correct the wrong ones. a. Mendeleev arranged elements in the ascending order of atomic number. b. The elements in the groups from 3 to 12 are called representative elements. c. The elements belong to 18th group is known as noble elements. d. Actinoides are also known as 'rear earths'. e. If there are four electrons in the outermost shell of an atom, it will be a 4th group element. f. If an atom has four shells, its period will be four. g. Inner transition elements belong to 6th & 7th groups. h. In a period, the size of atom increases with the increase of nuclear charge. 56. Complete the second pair according to the first. a. Mendeleev: Eight groups; Moseley : ........ b. Mendeleev: Atomic mass; Moseley: ....... c. Eka Aluminium: Gallium; ...........: Germanium. d. Group. I: Alkali metals; Group. II: ......... e. Group. I: One electron in the outermost shell; Group.18: ............. 57.Atomic number of magnesium (Mg) is 12 and that of chlorine (Cl) is 17. a. Find out their period and group from their electronic configuration. b. Which of the two is larger one? Justify your answer. c. Of the two elements which is possessed high electro negativity? 58. 4,12,15 and 10 are the atomic numbers of the elements P,Q,R&S respectively. Write down their electronic configuration and answer the following questions. a. Find out the elements belong to the same group. Of these which is the larger atom? Justify your answer. b. Find out the elements belong to the same period? Which of the two possessed higher ionisation energy? c. Identify the noble element from the elements given. www.shenischool.in To Join our whatsapp Group?Telegram SMS your Name to 9447490316
