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CLASSIFICATION OF ELEMENTS AND PERIODICITY IN PROPERTIES
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CLASSIFICATION OF ELEMENTS AND PERIODICITY IN PROPERTIES
Very Short Answer Questions
Q1. What is the difference in the approach between the Mendeleev's periodic law and the modern periodic law ?
Q2. In terms of period and group, where would you locate the element with Z = 114?
Q3. Write the atomic number of the element, present in the third period and seventeenth group of the periodic table.
Q4. Which element do you think would have been named by (a) Lawrence Berkeley Laboratory (b) Seaborg's group
Q5. Why do elements in the same group have similar physical and chemical properties?
Q6. What are representative elements? Give their valence shell configuration.
Q7. Justify the position of f-block elements in the periodic table.
Q8. An element X has atomic number 34. Give its position in the periodic table.
Q9. What factors impart characteristic properties to the transition elements ?
Q10. Give the outer shells configuration of d-block and f-block elements.
Q11. State and give one example for Doberciner's law of triads and Newland's law of octaves.
Q12. Name the anomalous pairs of elements in the Mendaleev's periodic table.
Q13. How does atomic radius vary in a period and in a group? How do you explain the variation?
Q14. Among $\ce{ N^{-3},0^{-2},F^-, Na^+, Mg^{+2}}$ and$\ce{ Al^{+3} }$.(a) What is common in them? (b). Arrange them in the increasing ionic radii.
Q15. What is the significance of the term isolated gaseous atom while defining the ionization enthalpy.
Q16. Energy of an electron in the ground state of the hydrogen atom is$\ce{ -2.18×10^{-18}}$ J.
Q17. Calculate the ionisation enthalpy of atomic hydrogen in terms of $\ce{ Jmol^-}$.
Q18. Ionization enthalpy, $\ce{ (IE_1)}$ of O is less than that of N- explain.
Q19. Which in each pair of elements has a more negative electron gain enthalpy? a). O or F b). For Cl
Q20. What are the major differences between metals and non-metals?
Q21. Use the periodic table to identify elements a). With 5 electrons in the outer subshell b) Would tend to lose two electrons c). Would tend to gain two electrons
Q22. Give the outer electronic configuration of s, p,d and f-block elements.
Q23. Write the increasing order of the metallic character among the elements $\ce{ B, Al, Mg }$and$\ce{ K.}$
Q24. Write the correct increasing order of non-metallic character for $\ce{ B, C, N, F}$ and $\ce{ St.}$
Q25. Write the correct increasing order of chemical reactivity in terms of oxidizing property for $\ce{ N,O, F}$ and $\ce{ Cl.}$
Q26. What is electronegativity? How is this useful in understanding the nature of elements?
Q27. What is screening effect? How is it related to$\ce{ IE}$?
Q28. How are electronegativity and metallic & non-metallic characters related ?
Q29. What is the valency possible to Arsenic with respect to oxygen and hydrogen?
Q30. What is an amphoteric oxide ? Give the formula of an amphoteric oxide formed by an element of group13.
Q31. Name the most electronegative element. Is it also having the highest electron gain enthalpy? Why or Why not?
Q32. What is diagonal relation? Give one pair of elements, that have this relation.
Q33. How does the nature of oxides var, in the third period?
Q34. Radii of iron atom and its ions follow $\ce{ Fe > Fe^{2+} > Fe^{3+}}$ explain.
Q35. $\ce{ IE_2> IE_1}$ for a given element - why?
Q36. What is lanthanide contraction? Give one of its consequences.
Q37. What is the atomic number of the element, having maximum number of unpaired 2p electrons ? To which group does it belong?
Q38. Sodium is strongly metallic, while chlorine is strongly non-metallie explain.
Q39. Why are zero group elements called noble gases or inert gases?
Q40. Select in each pair, the one having lower ionization energy and explain the reason. a). $\ce{I}$ and $\ce{I^-}$ b). $\ce{Br}$ and $\ce{k}$ c). $\ce{Li}$ and $\ce{Li^+}$ d). $\ce{Be}$ and $\ce{B}$ e). $\ce{O}$ and $\ce{S}$ f). $\ce{Be}$ and $\ce{B}$ g).$\ce{N}$ and $\ce{O}$
Q41. $\ce{IE}$,of $\ce{OIE_2}$of N-Explain
Q42. $\ce{Na^+}has higher value of ionization energy than Ne, though both have same electronic configuration Explain.
Q43. Which in each pair of elements has a more electronegative gain enthalpy? Explain. a). $\ce{N}$ and $\ce{O}$ b). $\ce{F}$ and $\ce{Cl}$
Q44. Electron affinity of chlorine is more than that of fluorine explain.
Q45. Which in each has higher electron affinity? a). $\ce{F}$ and $\ce{Cl^-}$ b). $\ce{O}$ and $\ce{O^-}$ c). $\ce{Na^+}$ and $\ce{F}$ d). $\ce{F}$ and $\ce{F^-}$
Q46. Arrange the following in order of increasing ionic radius: a). $\ce{ Cl^-, P^{-3}, S^{-2}, F^-}$ b). $\ce{ Al^{+3}, Mg^{+2}, Na^+, O^{-2}, F^-}$ c). $\ce{ Na^+, Mg^{+2}, K^+}$
Q47. $\ce{ Mg^{+2}}$ is smaller than $\ce{O^{-2}}$ in size, though both have same electronic configuration - explain.
Q48. Among the elements $\ce{ B, Al, C}$ and $\ce{ Si}$ a). Which has the highest first ionization enthalpy? b). Which has the most negative electron gain enthalpy? c). Which has the largest atomic radius? d). Which has the most metallic character?
Q49. Consider the elements$\ce{ N, P, O}$ and $\ce{ S}$and arrange them in order of: a). Increasing first ionization enthalpy b). Increasing negative electron gain enthalpy c). Increasing non-metallic character
Q50. Arrange in given order: a). Increasing $\ce{ EA: O, S}$ and $\ce{ Se}$ b). Increasing $\ce{ IE: Na, K}$ and Rb c). Increasing radius:$\ce{ I^- , I^+}$and $\ce{I}$ d). Increasing electronegativity: $\ce{ F, Cl, Br,I}$ e). Increasing$\ce{ EA: F, Cl, Br,I}$ f). Increasing radius:$\ce{ Fe, Fe^{+2}, Fe^{+3}}$
Q51. a). Name the element with highest ionization enthalpy b). Name the family with highest value of ionization enthalpy. c). Which element possesses highest electron affinity? d). Name unknown elements at the time of Mendeleef e). Name any two typical elements.
Q52. a). Name any two bridge elements. b). Name two pairs showing diagonal relationship. c). Name two transition elements. d). Name two rare earths. e). Name two transuranic elements.
Q1. On the basis of quantum numbers, Justify that the 6th period of the periodic table should have 32 elements.
Q2. How did Moseley's work on atomic numbers? Show that atomic number is a fundamental property better than atomic weight ?
Q3. State modern periodic law. How many groups and periods are present in the long form of the periodic table?
Q4. Why f-block elements are placed below the main table ?
Q5. Mention the number of elements present in each of the periods in the long form periodic table.
Q6. Give the outer orbit general electronic configuration of a). Noble gases b). Representative elements c). Transition elements d). Inner transition elements
Q7. Give any four characteristic properties of transition elements.
Q8. What are rare earths and transuranic elements ?
Q9. What is isoelectronic series? Name a series that will be isoelectronic with each of the following atoms or ions. a). $\ce{ F^-}$ b). $\ce{Ar}$ c). $\ce{He}$ d). $\ce{Rb^+}$
Q10. Explain why cation is smaller and anion is larger in radif than their parent atoms.
Q11. Arrange the second period elements in the increasing order of their first ionization enthalpies. Explain why Be has higher $\ce{ IE_1}$ than $\ce{ B}$.
Q12. $\ce{IE_1}$ of Na is less than that of $\ce{ Mg}$ but $\ce{ IE_2}$ of $\ce{ Na}4is higher than that of $\ce{ Mg}$explain.
Q13. What are the various factors due to which the $\ce{ IE}$ of the main group elements tends to decrease down a group ?
Q14. The first ionisation enthalpy values (in $\ce{ kJ mol^-1}$) of group 13 elements are: B -801 Al-577 Ga-579 In-558 Tl-589 How do you explain this deviation from the general trend ?
Q15. Would you expect the second electron gain enthalpy of oxygen as positive, more negative or less negative than the fürst? Justify.
Q16. What is the basic difference between the electron gain enthalpy and electropositivity?
Q17. Would you expect $\ce{ IE_1}$ for two isotopes of the same element to be the same or different? Justify.
Q18. Increasing order of reactivity among group-1 elements is $\ce{ LiCl> Br> I}$ explain.
Q19. Assign the position of the element having outer electronic configuration. a).$\ce{ns^2 np^4}$ for $\ce{n=3}$ b). $\ce{(n-1)d^2 ns^2}$ for $\ce{n=4}$
Q20. Predict the formulae of the stable binary compounds that would be formed by the combination of the following pairs of elements. a). $\ce{Li}$ and $\ce{O}$ b) $\ce{Mg}$ and $\ce{N}$ c). $\ce{Al}$ and $\ce{I}$ d). $\ce{Si}$ and $\ce{O}$ e). $\ce{P}$ and $\ce{Cl}$ f). Element with atomic number 30 and $\ce{Cl}$
Q21. Write a note on the variation of metallic nature in a group and in a period.
Q22. How does the covalent radius increase in group- 7?
Q23. Which element of 3 period has the highest $\ce{IE_1}$? Explain the variation of $\ce{IE_1}$ in this period.
Q24. What is valency of an element? How does it vary with respect to hydrogen in the third period?
Q25. What is diagonal relationship? Give a pair of elements having diagonal relationship. Why do they show this relation?
Q26. What is lanthanide contraction? What are its consequences ?
Q27. The first $\ce{IP}$ of lithium is $\ce{5.41 eV}$ and electron affinity of $\ce{Cl}$ is$\ce{ -3.61eV}$. Calculate $\ce{\Delta H}$ in mol for the reaction: $\ce{ Li_{(g)}+Cl_{(g)} -> Li^+ _{(g)}+Cl^-_{(g)}}$
Q28. How many Cl atoms can you ionize in the process $\ce{Cl->CI^+ + e}$ by the energy liberated for the process $\ce{Cl + e ->CI^- }$ for one Avogadro number of atoms. Given $\ce{IP = 13.0 eV}$ and $\ce{EA=3.60 eV}$. Avogadro number $\ce{=6×10^{23}}$
Q29. The electron gain enthalpy of chlorine is $\ce{3.7 eV}$. How much energy in kcal is released when 2g of chlorine atoms is completely converted to $\ce{Cl^-}$ ions in the gaseous state? (leV 23.06kcal)
Q1. Write an essay on $\ce{s, p,d}$ and $\ce{ f }$ block elements
Q2. Relate the electronic configuration of elements and their properties in the classification of elements.
Q3. Discuss the classification of elements by Mendaleev'
Q4. From a study of properties of neighbouring elements, the properties of an unknown element can be predicted Justify with an example.
Q5. Discuss the construction of long form periodic table.
Q6. Discuss the relation between the number of electrons filled into the sub energy levels of an orbit and the maximum number of elements present in a period.
Q7. What is a periodic property? How the following properties vary in a group and in a period? Explain a) Atomic radius b) Electron gain enthalpy.
Q8. What is a periodic property? How the following properties vary in a group and in a period?
Q9. Explain (a). $\ce{IE}$ (b).$\ce{ EN}$
Q10. Write a note on (a). Atomic radius (b). Metallic radius (c). Covalent radius
Q11. Define $\ce{IE_1}$ and $\ce{IE_2}$. Why is $\ce{IE_2 >IE_1}$ for a given atom? Discuss the factors that effect $\ce{IE}$ of an element.
Q12. How do the following properties change in group-1 and in the third period ? Explain with example. (a). Atomic radius (b). IE (C). EA (d). Nature of oxides
Q13. Define electron gain enthalpy. How it varies in a group and in a period? Why is the electron gain enthalpy of $\ce{O \,\, or\,\, F}$ is less negative than that of the succeeding element in the group?
Q14. (a). What is electronegativity? (b). How does it vary in a group and in a period ?
Q15. Explain the following (a). Valency (b). Diagonal relation (c). Variation of nature of oxides in the Group - 1