Chemistry Questions

  1. Define periodic table.
  2. Define classification of elements, the need of classification and its importance.
  3. Various attempts have been made to classify the elements from time to time. Discuss these historical developments.
  4. Explain modern periodic table in detail.
    OR
    What is modern periodic law? Discuss in detail modern periodic law.
    OR
    How is the modern periodic table different from Mendeleev's periodic table?
  5. Discuss Modern Periodic Table or Long form of periodic table.
  6. Define periods. How many periods are there in the long form of the periodic table?
  7. What do you mean by group? Explain different groups of the periodic table.
  8. Write names of some groups in the periodic table.
  9. Write the order in which the orbitals fill up according to Aufbau's principle.
  10. Write the maximum number of electrons accommodated in s-orbital, p-orbital, d-orbital, and f-orbital.
  11. Discuss the position of different blocks of the elements in the periodic table.
  12. Write down rules for determining the period of an element and the group of an element.
  13. Look at the periodic table and write the number of elements in the relevant period in the table. Table Number of elements in the periods of the periodic table.
  14. Define periods and groups.
  15. What was Dobereiner's contribution towards the classification of elements?
  16. State Mendeleev's periodic law.
  17. Why and how are elements arranged in a period?
  18. How did Newlands arrange the elements?
  19. What is the periodic law? And who introduced the name "Periodic Table"?
  20. Why was an improvement made in Mendeleev's periodic table?
  21. How many elements are placed in the 4th period?
  22. From which element does the lanthanide series start?
  23. From which period does the actinide series start?
  24. How many elements are there in the 3rd period? Write their names and symbols.
  25. What do you mean by a group in a periodic table?
  26. What is the reason for arranging elements in a group?
  27. Why are the elements called s or p block elements?
  28. Write down the names of elements of group 1 with their symbols.
    Predict the period of iodine metal.
    Predict the group number of the Cl atom.
    a) Which letter(s) (W, X, Y, Z) represent(s) the p, d, and s block of the periodic table?
  29. Identify the group, period, and block of the following elements on the basis of electronic configuration.
    1) Al (atomic number = 13)
    2) K (atomic number = 19)
  30. Identify the group and period of the following elements on the basis of electronic configuration.
    A 14 Si 28
    B 16 S 32
    C 9 F 19
    D 18 Ar 40
  31. Electronic configuration of atoms of some elements are given below. Classify them into groups and periods.
    a) 1s2 2s2
    b) 1s2 2s2 2p3
    c) 1s2 2s2 2p4
    d) 1s2 2s1 2p6 3s2
    e) 1s2 2s2 2p6 3s2 3p5
    f) 1s2 2s2 2p6 3s2 3p3
  32. Electronic configuration of atoms of some elements are given below. Place them into groups and periods.
  33. Discuss the relationship between group number and charge on an ion.
  34. Find out the position of the following elements in the periodic table from the electronic configuration:
    (a) Nitrogen (atomic number: 7)
    (b) Oxygen (atomic number: 8)
  35. Obtain the valence shell configuration of Al and S from their position in the periodic table.
  36. Why do group 1 elements form ions with a +1 charge?
  37. How do Group 17 elements achieve a stable electron configuration through ion formation?
  38. What is the charge of ions typically formed by elements in Group 2, and why?
  39. Define the shielding effect and explain its significance in the context of atomic structure. Using Sodium (Na) as an example, describe how the shielding effect operates in terms of its electron configuration. Discuss the trends in the shielding effect across a period and down a group in the periodic table and explain how these trends affect atomic size, ionization energy, and electron affinity.
  40. Choose the elements whose atoms you expect to have a greater shielding effect.
    (a) Be or Mg
    (b) C or Si
  41. Choose the element whose atoms you expect to have a smaller shielding effect.
    (a) F or Cl
    (b) Li or Na
    (c) B or Al
  42. Define the periodicity of properties in the context of the periodic table. Explain the trends in atomic radius:
    (a) Across a period from left to right.
    (b) Down a group from top to bottom.
  43. Choose the element whose atom you expect to have a larger atomic radius in each of the following pairs.
    (a) Mg, Al
    (b) C, Si
  44. Using the periodic table but without looking at the figure 4.4, choose the element whose atom you expect to have a smaller atomic radius in each of the following pairs.
    (a) O or S
    (b) O or F
  45. Define ionization energy and explain its significance in atomic structure. Differentiate between first and second ionization energy with examples. Discuss the factors affecting ionization energy and analyze the trends across a period and within a group in the periodic table.
  46. Which atom has a greater shielding effect? Li or Na?
  47. Choose the element whose atom you expect to have smaller ionization energy in each of the following pairs.
    (a) B, C
    (b) N, P
  48. Which atom has the smaller ionization energy?
    (a) B or N
    (b) Be or Mg
    (c) C or Si
  49. Define electron affinity and explain its significance in the formation of anions. Differentiate between first and second electron affinity with suitable examples, including the specific cases of chlorine and oxygen. Discuss the factors that affect electron affinity and analyze the trends in electron affinity both within a group and across a period in the periodic table.
  50. Define electronegativity and explain its significance in the formation of covalent bonds. Differentiate between polar and non-polar covalent bonds with examples. Discuss the factors that affect electronegativity and compare the trends in electronegativity across a period and within a group in the periodic table, using specific examples from the second period and Group 17. Additionally, mention the different electronegativity scales used to measure this property.
  51. Move across the second period from left to right and note down the variation in electronegativity values.
  52. Move across the third period from left to right and note down the variation in electronegativity values.
  53. Make a generalization about the variation in electronegativity across a period and write the reason.
  54. Move from top to bottom in Groups IA and IIA and note down the variation in electronegativity values.
  55. Move from top to bottom in Groups VIA and VIIA and note down the variation in electronegativity values.
  56. Make a generalization about the trend in electronegativity values in a group. Give a reason.
  57. Discuss metallic character and write the trends in the periodic table.
  58. What is the definition of atomic radius?
  59. Why does the size of atoms decrease in a period?
  60. What is ionization energy, and why is the second ionization energy of an element higher than the first one? Also, what is the trend of ionization energy in a group?
  61. Why is it difficult to remove an electron from halogens?
  62. Which element has the highest electronegativity?
  63. What is the general trend in ionization energy as you move down a group in the periodic table?
  64. Compare and contrast the trends in atomic radius and ionization energy as you move across a period and down a group in the periodic table.
  65. Define electron affinity and explain its trend across a period in the periodic table.
  66. Choose the element you expect to have higher metallic character in each of the following pairs.
    (a) Na or K
    (b) Na or Mg
  67. Which element has lower metallic character?
    (a) La or K
    (b) Mg or Ca
    (c) Compare and contrast ionization energy and electron affinity.
  68. Define reactivity. Discuss its trends along periods and in groups.
  69. Define density. Discuss its trends along periods and groups.
  70. Write down a few characteristic properties of Alkali metals.
  71. Predict the properties of some elements in Group 1.
  72. How to determine the position of an unknown element in the periodic table using its electronic configuration and provide examples to illustrate this process. Suppose you have an unknown element having atomic number 19, and you want to determine its position in the periodic table.
  73. Shed some light on different properties of transition elements.
  74. What are lanthanide and actinide series?
  75. What are halogens? Discuss their properties in detail.
  76. Which of the following displacement reactions will occur?
    (1) Cl2(g) + 2NaF(aq) → 2NaCl(aq) + F2(g)
    (2) Br2(l) + 2KI(aq) → 2KBr(aq) + I2(s)
    (3) Cl2(g) + 2KBr(aq) → 2KCl(aq) + Br2(l)
    (4) Cl2(g) + 2NaI(aq) → 2NaCl(aq) + I2(s)
  77. What are noble gases? Discuss their same characters.
  78. Write down a comparison of general properties of metals and non-metals.
  79. Why do elements in the same group have similar chemical properties?
  80. How does the valence electron configuration affect an element's chemical behavior?
  81. What role does the outermost shell play in determining an element's reactivity?
  82. How do similar valence electrons lead to similar types of chemical bonds?
  83. In what way does electronic configuration influence the formation of ions by elements in the same group?
  84. What characteristics distinguish alkali metals from alkaline earth metals in the periodic table?
  85. How do halogens differ in reactivity compared to noble gases?