Q3.2:

Which important property did Mendeleev use to classify the elements in his periodic table and did he stick to that?

More Questions from Class 11 Chemistry Classification of Elements and Periodicity in Properties EXERCISES

• Q3.1: What is the basic theme of organisation in the periodic table?
• Q3.1: What is the basic theme of organisation in the periodic table?
• Q3.10: How do atomic radius vary in a period and in a group? How do you explain the variation?
• Q3.10: How do atomic radius vary in a period and in a group? How do you explain the variation?
• Q3.11(i): What do you understand by isoelectronic species? Name a species that will be isoelectronic with each of the following atoms or ions. (i) $F^{-}$
• Q3.11(i): What do you understand by isoelectronic species? Name a species that will be isoelectronic with each of the following atoms or ions. (i) (F^{-})
• Q3.11(ii): What do you understand by isoelectronic species? Name a species that will be isoelectronic with each of the following atoms or ions. (ii) $Ar$
• Q3.11(ii): What do you understand by isoelectronic species? Name a species that will be isoelectronic with each of the following atoms or ions. (ii) Ar
• Q3.11(iii): What do you understand by isoelectronic species? Name a species that will be isoelectronic with each of the following atoms or ions. (iii) $Mg^{2+}$
• Q3.11(iii): What do you understand by isoelectronic species? Name a species that will be isoelectronic with each of the following atoms or ions. (iii) (Mg^{2+})
• Q3.11(iv): What do you understand by isoelectronic species? Name a species that will be isoelectronic with each of the following atoms or ions. (iv) $Rb^{+}$
• Q3.11(iv): What do you understand by isoelectronic species? Name a species that will be isoelectronic with each of the following atoms or ions. (iv) (Rb^{+})
• Q3.12(a): Consider the following species : $N^{3-}$, $O^{2-}$, $F^{-}$, $Na^{+}$, $Mg^{2+}$ and $Al^{3+}$ (a) What is common in them?
• Q3.12(a): Consider the following species: (N^{3-}), (O^{2-}), (F^{-}), (Na^{+}), (Mg^{2+}) and (Al^{3+}) (a) What is common in them?
• Q3.12(b): Consider the following species : $N^{3-}$, $O^{2-}$, $F^{-}$, $Na^{+}$, $Mg^{2+}$ and $Al^{3+}$ (b) Arrange them in the order of increasing ionic radii.
• Q3.12(b): Consider the following species: (N^{3-}), (O^{2-}), (F^{-}), (Na^{+}), (Mg^{2+}) and (Al^{3+}) (b) Arrange them in the order of increasing ionic radii.
• Q3.13: Explain why cation are smaller and anions larger in radii than their parent atoms?
• Q3.13: Explain why cation are smaller and anions larger in radii than their parent atoms?
• Q3.14: What is the significance of the terms — ‘isolated gaseous atom’ and ‘ground state’ while defining the ionization enthalpy and electron gain enthalpy?
• Q3.14: What is the significance of the terms — ‘isolated gaseous atom’ and ‘ground state’ while defining the ionization enthalpy and electron gain enthalpy? Hint : Requirements for comparison purposes.
• Q3.15: Energy of an electron in the ground state of the hydrogen atom is $-2.18 imes 10^{-18}J$. Calculate the ionization enthalpy of atomic hydrogen in terms of $J mol^{-1}$.
• Q3.15: Energy of an electron in the ground state of the hydrogen atom is (–2.18 \times 10^{-18}J). Calculate the ionization enthalpy of atomic hydrogen in terms of (J mol^{-1}). Hint: Apply the idea of mole concept to derive the answer.
• Q3.16(i): Among the second period elements the actual ionization enthalpies are in the order $Li < B < Be < C < O < N < F < Ne$. Explain why (i) $Be$ has higher $\Delta_{i} H$ than $B$
• Q3.16(i): Among the second period elements the actual ionization enthalpies are in the order (Li < B < Be < C < O < N < F < Ne). Explain why (i) Be has higher (\Delta_{i}H) than B
• Q3.16(ii): Among the second period elements the actual ionization enthalpies are in the order $Li < B < Be < C < O < N < F < Ne$. Explain why (ii) $O$ has lower $\Delta_{i} H$ than $N$ and $F$?
• Q3.16(ii): Among the second period elements the actual ionization enthalpies are in the order (Li < B < Be < C < O < N < F < Ne). Explain why (ii) O has lower (\Delta_{i}H) than N and F?
• Q3.17: How would you explain the fact that the first ionization enthalpy of sodium is lower than that of magnesium but its second ionization enthalpy is higher than that of magnesium?
• Q3.17: How would you explain the fact that the first ionization enthalpy of sodium is lower than that of magnesium but its second ionization enthalpy is higher than that of magnesium?
• Q3.18: What are the various factors due to which the ionization enthalpy of the main group elements tends to decrease down a group?
• Q3.18: What are the various factors due to which the ionization enthalpy of the main group elements tends to decrease down a group?
• Q3.19: The first ionization enthalpy values (in $kJ mol^{-1}$) of group 13 elements are : B Al Ga In Tl 801 577 579 558 589 How would you explain this deviation from the general trend ?
• Q3.19: The first ionization enthalpy values (in (kJ mol^{-1})) of group 13 elements are : B 801, Al 577, Ga 579, In 558, Tl 589 How would you explain this deviation from the general trend ?
• Q3.2: Which important property did Mendeleev use to classify the elements in his periodic table and did he stick to that?
• Q3.20(i): Which of the following pairs of elements would have a more negative electron gain enthalpy? (i) $O$ or $F$
• Q3.20(i): Which of the following pairs of elements would have a more negative electron gain enthalpy? (i) O or F
• Q3.20(ii): Which of the following pairs of elements would have a more negative electron gain enthalpy? (ii) $F$ or $Cl$
• Q3.20(ii): Which of the following pairs of elements would have a more negative electron gain enthalpy? (ii) F or Cl
• Q3.21: Would you expect the second electron gain enthalpy of $O$ as positive, more negative or less negative than the first? Justify your answer.
• Q3.21: Would you expect the second electron gain enthalpy of O as positive, more negative or less negative than the first? Justify your answer.
• Q3.22: What is the basic difference between the terms electron gain enthalpy and electronegativity?
• Q3.22: What is the basic difference between the terms electron gain enthalpy and electronegativity?
• Q3.23: How would you react to the statement that the electronegativity of $N$ on Pauling scale is 3.0 in all the nitrogen compounds?
• Q3.23: How would you react to the statement that the electronegativity of N on Pauling scale is 3.0 in all the nitrogen compounds?
• Q3.24(a): Describe the theory associated with the radius of an atom as it (a) gains an electron
• Q3.24(a): Describe the theory associated with the radius of an atom as it (a) gains an electron
• Q3.24(b): Describe the theory associated with the radius of an atom as it (b) loses an electron
• Q3.24(b): Describe the theory associated with the radius of an atom as it (b) loses an electron
• Q3.25: Would you expect the first ionization enthalpies for two isotopes of the same element to be the same or different? Justify your answer.
• Q3.25: Would you expect the first ionization enthalpies for two isotopes of the same element to be the same or different? Justify your answer.
• Q3.26: What are the major differences between metals and non-metals?
• Q3.26: What are the major differences between metals and non-metals?
• Q3.27(a): Use the periodic table to answer the following questions. (a) Identify an element with five electrons in the outer subshell.
• Q3.27(a): Use the periodic table to answer the following questions. (a) Identify an element with five electrons in the outer subshell.
• Q3.27(b): Use the periodic table to answer the following questions. (b) Identify an element that would tend to lose two electrons.
• Q3.27(b): Use the periodic table to answer the following questions. (b) Identify an element that would tend to lose two electrons.
• Q3.27(c): Use the periodic table to answer the following questions. (c) Identify an element that would tend to gain two electrons.
• Q3.27(c): Use the periodic table to answer the following questions. (c) Identify an element that would tend to gain two electrons.
• Q3.27(d): Use the periodic table to answer the following questions. (d) Identify the group having metal, non-metal, liquid as well as gas at the room temperature.
• Q3.27(d): Use the periodic table to answer the following questions. (d) Identify the group having metal, non-metal, liquid as well as gas at the room temperature.
• Q3.28: The increasing order of reactivity among group 1 elements is $Li < Na < K < Rb < Cs$ whereas that among group 17 elements is $F > Cl > Br > I$. Explain.
• Q3.28: The increasing order of reactivity among group 1 elements is (Li < Na < K < Rb < Cs) whereas that among group 17 elements is (F > CI > Br > I). Explain.
• Q3.29: Write the general outer electronic configuration of $s$-, $p$-, $d$- and $f$- block elements.
• Q3.29: Write the general outer electronic configuration of s-, p-, d- and f- block elements.
• Q3.3: What is the basic difference in approach between the Mendeleev’s Periodic Law and the Modern Periodic Law?
• Q3.3: What is the basic difference in approach between the Mendeleev’s Periodic Law and the Modern Periodic Law?
• Q3.30(i): Assign the position of the element having outer electronic configuration (i) $ns^{2}np^{4}$ for $n=3$
• Q3.30(i): Assign the position of the element having outer electronic configuration (i) (ns^{2}np^{4}) for (n=3)
• Q3.30(ii): Assign the position of the element having outer electronic configuration (ii) $(n-1)d^{2}ns^{2}$ for $n=4$, and
• Q3.30(ii): Assign the position of the element having outer electronic configuration (ii) ((n-1)d^{2}ns^{2}) for (n=4)
• Q3.30(iii): Assign the position of the element having outer electronic configuration (iii) $(n-2) f^{7} (n-1)d^{1}ns^{2}$ for $n=6$, in the periodic table.
• Q3.30(iii): Assign the position of the element having outer electronic configuration (iii) ((n-2)f^{7}(n-1)d^{1}ns^{2}) for (n=6), in the periodic table.
• Q3.31(a): The first ($\Delta_{i}H_{1}$) and the second ($\Delta_{i}H_{2}$) ionization enthalpies (in kJ $mol^{-1}$) and the ($\Delta_{eg}H$) electron gain enthalpy (in kJ $mol^{-1}$) of a few elements are given below: Elements $\Delta H_{1}$ $\Delta H_{2}$ $\Delta_{eg}H$ I 520 7300 –60 II 419 3051 –48 III 1681 3374 –328 IV 1008 1846 –295 V 2372 5251 +48 VI 738 1451 –40 Which of the above elements is likely to be : (a) the least reactive element.
• Q3.31(a): The first ((\Delta_{i}H_{1})) and the second ((\Delta_{i}H_{2})) ionization enthalpies (in (kJ mol^{-1})) and the ((\Delta_{eg}H)) electron gain enthalpy (in (kJ mol^{-1})) of a few elements are given below: Which of the above elements is likely to be : (a) the least reactive element.
• Q3.31(b): The first ($\Delta_{i}H_{1}$) and the second ($\Delta_{i}H_{2}$) ionization enthalpies (in kJ $mol^{-1}$) and the ($\Delta_{eg}H$) electron gain enthalpy (in kJ $mol^{-1}$) of a few elements are given below: Elements $\Delta H_{1}$ $\Delta H_{2}$ $\Delta_{eg}H$ I 520 7300 –60 II 419 3051 –48 III 1681 3374 –328 IV 1008 1846 –295 V 2372 5251 +48 VI 738 1451 –40 Which of the above elements is likely to be : (b) the most reactive metal.
• Q3.31(b): The first ((\Delta_{i}H_{1})) and the second ((\Delta_{i}H_{2})) ionization enthalpies (in (kJ mol^{-1})) and the ((\Delta_{eg}H)) electron gain enthalpy (in (kJ mol^{-1})) of a few elements are given below: (b) the most reactive metal.
• Q3.31(c): The first ($\Delta_{i}H_{1}$) and the second ($\Delta_{i}H_{2}$) ionization enthalpies (in kJ $mol^{-1}$) and the ($\Delta_{eg}H$) electron gain enthalpy (in kJ $mol^{-1}$) of a few elements are given below: Elements $\Delta H_{1}$ $\Delta H_{2}$ $\Delta_{eg}H$ I 520 7300 –60 II 419 3051 –48 III 1681 3374 –328 IV 1008 1846 –295 V 2372 5251 +48 VI 738 1451 –40 Which of the above elements is likely to be : (c) the most reactive non-metal.
• Q3.31(c): The first ((\Delta_{i}H_{1})) and the second ((\Delta_{i}H_{2})) ionization enthalpies (in (kJ mol^{-1})) and the ((\Delta_{eg}H)) electron gain enthalpy (in (kJ mol^{-1})) of a few elements are given below: (c) the most reactive non-metal.
• Q3.31(d): The first ($\Delta_{i}H_{1}$) and the second ($\Delta_{i}H_{2}$) ionization enthalpies (in kJ $mol^{-1}$) and the ($\Delta_{eg}H$) electron gain enthalpy (in kJ $mol^{-1}$) of a few elements are given below: Elements $\Delta H_{1}$ $\Delta H_{2}$ $\Delta_{eg}H$ I 520 7300 –60 II 419 3051 –48 III 1681 3374 –328 IV 1008 1846 –295 V 2372 5251 +48 VI 738 1451 –40 Which of the above elements is likely to be : (d) the least reactive non-metal.
• Q3.31(d): The first ((\Delta_{i}H_{1})) and the second ((\Delta_{i}H_{2})) ionization enthalpies (in (kJ mol^{-1})) and the ((\Delta_{eg}H)) electron gain enthalpy (in (kJ mol^{-1})) of a few elements are given below: (d) the least reactive non-metal.
• Q3.31(e): The first ($\Delta_{i}H_{1}$) and the second ($\Delta_{i}H_{2}$) ionization enthalpies (in kJ $mol^{-1}$) and the ($\Delta_{eg}H$) electron gain enthalpy (in kJ $mol^{-1}$) of a few elements are given below: Elements $\Delta H_{1}$ $\Delta H_{2}$ $\Delta_{eg}H$ I 520 7300 –60 II 419 3051 –48 III 1681 3374 –328 IV 1008 1846 –295 V 2372 5251 +48 VI 738 1451 –40 Which of the above elements is likely to be : (e) the metal which can form a stable binary halide of the formula $MX_{2}$($X$=halogen).
• Q3.31(e): The first ((\Delta_{i}H_{1})) and the second ((\Delta_{i}H_{2})) ionization enthalpies (in (kJ mol^{-1})) and the ((\Delta_{eg}H)) electron gain enthalpy (in (kJ mol^{-1})) of a few elements are given below: (e) the metal which can form a stable binary halide of the formula (MX_{2}) (X=halogen).
• Q3.31(f): The first ($\Delta_{i}H_{1}$) and the second ($\Delta_{i}H_{2}$) ionization enthalpies (in kJ $mol^{-1}$) and the ($\Delta_{eg}H$) electron gain enthalpy (in kJ $mol^{-1}$) of a few elements are given below: Elements $\Delta H_{1}$ $\Delta H_{2}$ $\Delta_{eg}H$ I 520 7300 –60 II 419 3051 –48 III 1681 3374 –328 IV 1008 1846 –295 V 2372 5251 +48 VI 738 1451 –40 Which of the above elements is likely to be : (f) the metal which can form a predominantly stable covalent halide of the formula $MX$ ($X$=halogen)?
• Q3.31(f): The first ((\Delta_{i}H_{1})) and the second ((\Delta_{i}H_{2})) ionization enthalpies (in (kJ mol^{-1})) and the ((\Delta_{eg}H)) electron gain enthalpy (in (kJ mol^{-1})) of a few elements are given below: (f) the metal which can form a predominantly stable covalent halide of the formula (MX) (X=halogen)?
• Q3.32(a): Predict the formulas of the stable binary compounds that would be formed by the combination of the following pairs of elements. (a) Lithium and oxygen
• Q3.32(a): Predict the formulas of the stable binary compounds that would be formed by the combination of the following pairs of elements. (a) Lithium and oxygen
• Q3.32(b): Predict the formulas of the stable binary compounds that would be formed by the combination of the following pairs of elements. (b) Magnesium and nitrogen
• Q3.32(b): Predict the formulas of the stable binary compounds that would be formed by the combination of the following pairs of elements. (b) Magnesium and nitrogen
• Q3.32(c): Predict the formulas of the stable binary compounds that would be formed by the combination of the following pairs of elements. (c) Aluminium and iodine
• Q3.32(c): Predict the formulas of the stable binary compounds that would be formed by the combination of the following pairs of elements. (c) Aluminium and iodine
• Q3.32(d): Predict the formulas of the stable binary compounds that would be formed by the combination of the following pairs of elements. (d) Silicon and oxygen
• Q3.32(d): Predict the formulas of the stable binary compounds that would be formed by the combination of the following pairs of elements. (d) Silicon and oxygen
• Q3.32(e): Predict the formulas of the stable binary compounds that would be formed by the combination of the following pairs of elements. (e) Phosphorus and fluorine
• Q3.32(e): Predict the formulas of the stable binary compounds that would be formed by the combination of the following pairs of elements. (e) Phosphorus and fluorine
• Q3.32(f): Predict the formulas of the stable binary compounds that would be formed by the combination of the following pairs of elements. (f) Element 71 and fluorine
• Q3.32(f): Predict the formulas of the stable binary compounds that would be formed by the combination of the following pairs of elements. (f) Element 71 and fluorine
• Q3.33: In the modern periodic table, the period indicates the value of :
• Q3.33: In the modern periodic table, the period indicates the value of :
• Q3.34: Which of the following statements related to the modern periodic table is incorrect?
• Q3.34: Which of the following statements related to the modern periodic table is incorrect?
• Q3.35: Anything that influences the valence electrons will affect the chemistry of the element. Which one of the following factors does not affect the valence shell?
• Q3.35: Anything that influences the valence electrons will affect the chemistry of the element. Which one of the following factors does not affect the valence shell?
• Q3.36: The size of isoelectronic species — $F^{-}$, $Ne$ and $Na^{+}$ is affected by
• Q3.36: The size of isoelectronic species — (F^{-}), Ne and (Na^{+}) is affected by
• Q3.37: Which one of the following statements is incorrect in relation to ionization enthalpy?
• Q3.37: Which one of the following statements is incorrect in relation to ionization enthalpy?
• Q3.38: Considering the elements $B$, $Al$, $Mg$, and $K$, the correct order of their metallic character is :
• Q3.38: Considering the elements B, Al, Mg, and K, the correct order of their metallic character is :
• Q3.39: Considering the elements $B$, $C$, $N$, $F$, and $Si$, the correct order of their non-metallic character is :
• Q3.39: Considering the elements B, C, N, F, and Si, the correct order of their non-metallic character is :
• Q3.4: On the basis of quantum numbers, justify that the sixth period of the periodic table should have 32 elements.
• Q3.4: On the basis of quantum numbers, justify that the sixth period of the periodic table should have 32 elements.
• Q3.40: Considering the elements $F$, $Cl$, $O$ and $N$, the correct order of their chemical reactivity in terms of oxidizing property is :
• Q3.40: Considering the elements F, Cl, O and N, the correct order of their chemical reactivity in terms of oxidizing property is :
• Q3.5: In terms of period and group where would you locate the element with $Z =114$?
• Q3.5: In terms of period and group where would you locate the element with (Z =114)?
• Q3.6: Write the atomic number of the element present in the third period and seventeenth group of the periodic table.
• Q3.6: Write the atomic number of the element present in the third period and seventeenth group of the periodic table.
• Q3.7(i): Which element do you think would have been named by (i) Lawrence Berkeley Laboratory
• Q3.7(i): Which element do you think would have been named by (i) Lawrence Berkeley Laboratory
• Q3.7(ii): Which element do you think would have been named by (ii) Seaborg’s group?
• Q3.7(ii): Which element do you think would have been named by (ii) Seaborg’s group?
• Q3.8: Why do elements in the same group have similar physical and chemical properties?
• Q3.8: Why do elements in the same group have similar physical and chemical properties?
• Q3.9: What does atomic radius and ionic radius really mean to you?
• Q3.9: What does atomic radius and ionic radius really mean to you?