Science and Technology I · Textbook solutions

Periodic Classification of Elements

Every solved example, exercise, and miscellaneous question — in the order the textbook teaches them. · 38 questions

Exercise

38 q
  1. Ex Q1
    Rearrange the columns 2 and 3 so as to match with the column 1.
    Column 1Column 2Column 3
    i. Triada. Lightest and negatively charged particle in all the atoms1. Mendeleev
    ii. Octaveb. Concentrated mass and positive charge2. Thomson
    iii. Atomic numberc. Average of the first and the third atomic mass3. Newlands
    iv. Periodd. Properties of the eighth element similar to the first4. Rutherford
    v. Nucleuse. Positive charge on the nucleus5. Dobereiner
    vi. Electronf. Sequential change in molecular formulae6. Moseley
  2. Choose the correct option and rewrite the statement.
    Ex Q2(a)
    The number of electrons in the outermost shell of alkali metals is......
    1. A.
      1
    2. B.
      2
    3. C.
      3
    4. D.
      7
  3. Ex Q2(b)
    Alkaline earth metals have valency 2. This means that their position in the modern periodic table is in .....
    1. A.
      Group 2
    2. B.
      Group16
    3. C.
      Period 2
    4. D.
      d-block
  4. Ex Q2(c)
    Molecular formula of the chloride of an element X is XCl. This compound is a solid having high melting point. Which of the following elements be present in the same group as X.
    1. A.
      Na
    2. B.
      Mg
    3. C.
      Al
    4. D.
      Si
  5. Ex Q2(d)
    In which block of the modern periodic table are the nonmetals found?
    1. A.
      s-block
    2. B.
      p-block
    3. C.
      d-block
    4. D.
      f-block
  6. An element has its electron configuration as 2,8,2. Now answer the following questions.
    Ex Q3(a)
    What is the atomic number of this element?
  7. Ex Q3(b)
    What is the group of this element?
  8. Ex Q3(c)
    To which period does this element belong?
  9. Ex Q3(d)
    With which of the following elements would this element resemble? (Atomic numbers are given in the brackets) N (7), Be (4) , Ar (18), Cl (17)
  10. Write down the electronic configuration of the following elements from the given atomic numbers. Answer the following question with explanation.
    Ex Q4(a)
    3_{3}Li, 14_{14}Si, 2_{2}He, 11_{11}Na, 15_{15}P Which of these elements belong to be period 3?
  11. Ex Q4(b)
    1_{1}H, 7_{7}N, 20_{20}Ca, 16_{16}S, 4_{4}Be, 18_{18}Ar Which of these elements belong to the second group?
  12. Ex Q4(c)
    7_{7}N, 6_{6}C, 8_{8}O, 5_{5}B, 13_{13}A1 Which is the most electronegative element among these?
  13. Ex Q4(d)
    4_{4}Be, 6_{6}C, 8_{8}O, 5_{5}B, 13_{13}A1 Which is the most electropositive element among these?
  14. Ex Q4(e)
    11_{11}Na, 15_{15}P, 17_{17}C1, 14_{14}Si, 12_{12}Mg Which of these has largest atoms?
  15. Ex Q4(f)
    19_{19}K, 3_{3}Li, 11_{11}Na, 4_{4}Be Which of these atoms has smallest atomic radius?
  16. Ex Q4(g)
    13_{13}A1, 14_{14}Si, 11_{11}Na, 12_{12}Mg, 16_{16}S Which of the above elements has the highest metallic character?
  17. Ex Q4(h)
    6_{6}C, 3_{3}Li, 9_{9}F, 7_{7}N, 8_{8}O Which of the above elements has the highest nonmetallic character?
  18. Write the name and symbol of the element from the description.
    Ex Q5(a)
    The atom having the smallest size.
  19. Ex Q5(b)
    The atom having the smallest atomic mass.
  20. Ex Q5(c)
    The most electronegative atom.
  21. Ex Q5(d)
    The noble gas with the smallest atomic radius.
  22. Ex Q5(e)
    The most reactive nonmetal.
  23. Write short notes.
    Ex Q6(a)
    Mendeleev's periodic law.
  24. Ex Q6(b)
    Structure of the modern periodic table.
  25. Ex Q6(c)
    Position of isotopes in the Mendeleev's and the modern periodic table.
  26. Write scientific reasons.
    Ex Q7(a)
    Atomic radius goes on decreasing while going from left to right in a period.
  27. Ex Q7(b)
    Metallic character goes on decreasing while going from left to right in a period.
  28. Ex Q7(c)
    Atomic radius goes on increasing down a group.
  29. Ex Q7(d)
    Elements belonging to the same group have the same valency.
  30. Ex Q7(e)
    The third period contains only eight elements even through the electron capacity of the third shell is 18.
  31. Write the names from the description.
    Ex Q8(a)
    The period with electrons in the shells K, L and M.
  32. Ex Q8(b)
    The group with valency zero.
  33. Ex Q8(c)
    The family of nonmetals having valency one.
  34. Ex Q8(d)
    The family of metals having valency one.
  35. Ex Q8(e)
    The family of metals having valency two.
  36. Ex Q8(f)
    The metalloids in the second and third periods.
  37. Ex Q8(g)
    Nonmetals in the third period.
  38. Ex Q8(h)
    Two elements having valency 4.