Periodic Table and Its Properties Exercise # 1

Exercise # 1 [Single Correct Choice Type Questions] 1. Which of the following is/are drawback of Mendeleev's periodic table : (A) Position of Hydrogen was uncertain. (B) No separate positions were given to isotopes of an element. (C) The order of increasing atomic mass was not strictly followed. (D) All of these 2. The period number in the long form of the periodic table is equal to : (A) magnetic quantum number of any element of the period. (B) atomic number of any element of the period. (C) maximum Principal quantum number of any element of the period. (D) maximum Azimuthal quantum number of any element of the period. 3. Which one of the following statements related to the modern periodic table is incorrect : (A) The p-block has 6 columns, because a maximum of 6 electrons can occupy all the orbitals in a p-subshell. (B) The d-block has 8 columns, because a maximum of 8 electrons can occupy all the orbitals in a d-subshell. (C) Each block contains a number of columns equal to the number of electrons that can occupy that subshell. (D) The block indicates value of Azimuthal quantum number () for the last subshell that received electrons in building up the electronic configuration. 4. Which is correct match ? (A) Eka silicon-Ge (B) Eka aluminium-Ga (C) Both (A) and (B) (D) None of these 5. The elements in which electrons are progressively filled in 4f-orbital are called : (A) actinoids (B) transition elements (C) lanthanoids (D) halogens 6. Atomic number of Ag is 47. In the same group, the atomic numbers of elements placed above and below Ag in Long form of periodic table will be : (A) 29, 65 (B) 39, 79 (C) 29, 79 (D) 39, 65 7. Element with electronic configuration as [Ar] 3d5 4s1 is placed in ___ in Modern periodic table : (A) IA (1st group), s-block (B) IB (7th group), d-block th (C) VIB (8 group), d-block (D) VIB (6th group), d-block 8. In modern periodic table, the element with atomic number Z = 118 will be : (A) Uuo ; Ununoctium ; alkaline earth metal (B) Uno ; Unniloctium ; transition metal (C) Uno ; Unniloctium ; alkali metal (D) Uuo ; Ununoctium ; noble gas 9. Which of the following is not an actinoid : (A) Curium (Z = 96) (B) Californium (Z = 98) (C) Uranium (Z = 92) (D) Terbium (Z = 65) 10. Which of the following statements is not correct regarding hydrogen : (A) It resembles halogens in some properties. (B) It resembles alkali metals in some properties. (C) It can be placed in 17th group of Modern periodic table. (D) It cannot be placed in 1st group of Modern periodic table. 11. The order of screening effect of electrons of s, p, d and f orbitals of a given shell of an atom on its outer shell electrons is (A) s > p > d > f (B) f > d > p > s (C) p < d < s > f (D) f > p > s > d PERIODIC TABLE AND ITS PROPERTIES 12. Which of the following is/are generally true regarding effective nuclear charge (Zeff) : (A) It increases on moving left to right in a period. (B) It remains almost constant on moving top to bottom in a group. (C) For isoelectronic species, as Z increases, Zeff decreases. (D) Both (A) and (B). 13. Which of the following is the correct order of size of the given species : (A) I > I– > I+ (B) I+ > I– > I (C) I > I+ > I– 14. (D) I– > I > I+ Match the correct atomic radius with the element : S.No. Element Code (i) Be (p) (ii) C (q) (iii) O (r) (iv) B (s) (v) N (t) (A) (i) – r, (ii) – q, (iii) – t, (iv) – s, (v) – p Atomic radius (pm) 74 88 111 77 66 (B) (i) – t, (ii) – s, (iii) – r, (iv) – p, (v) – q (C) (i) – r, (ii) – s, (iii) – t, (iv) – q, (v) – p (D) (i) – t, (ii) – p, (iii) – r, (iv) – s, (v) – q 15. Select correct statement(s) about radius of an atom : (A) Values of Vander waal's radii are larger than those of covalent radii because the Vander waal's forces are much weaker than the forces operating between atoms in a covalently bonded molecule. (B) The metallic radii are smaller than the Vander waal's radii, since the bonding forces in the metallic crystal lattice are much stronger than the Vander waal's forces. (C) Both (A) & (B) (D) None of these 16. Which of the following order of atomic / ionic radius is not correct ? (A) F < Cl < Br <  (B) Y3+ > Sr2+ > Rb+ (C) Nb  Ta 17. The size of isoelectronic species F–, Ne and Na+ is affected by : (A) nuclear charge (Z) (B) valence principal quantum number (n) (C) electron-electron interaction in the outer orbitals (D) none of the factors because their size is the same. 18. Which of the following order of radii is correct : (A) Li < Be < Mg (B) H+ < Li+ < H– (C) O < F < Ne (D) Li > Be > B (D) Li < Na < K < Cs < Rb 19. Which one of the following statements is incorrect in relation to ionisation enthalpy ? (A) Ionization enthalpy increases for each successive electron. (B) The greatest increase in ionization enthalpy is experienced on removal of electron from core of noble gas configuration. (C) End of valence electrons is marked by a big jump in ionization enthalpy. (D) Removal of electron from orbitals bearing lower n value is easier than from orbitals having higher n value. 20. The ionization enthalpy will be highest when the electron is to be removed from .............. if other factors are equal (A) s-orbital (B) p-orbital (C) d-orbital (D) f-orbital 21. Which represents alkali metals (i.e. 1st group metals) based on (IE)1 and (IE)2 values (in kJ/mol) ? (IE)1 (IE)2 (IE)1 (IE)2 (A) X 500 1000 (B) Y 600 2000 (C) Z 550 7500 (D) M 700 1400 22. Which of the following relation is correct with respect to first (I) and second (II) ionization enthalpies of potassium and calcium ? (A) ICa > IIK 23. 25. (B) 13.6, 14.6 (C) 13.6, 13.6 (A) Na < Mg > Al < Si (B) Na > Mg > Al > Si (C) Na < Mg < Al < Si (D) Na > Mg > Al < Si (D) 14.6, 14.6 Among halogens, the correct order of amount of energy released in electron gain (electron gain enthalpy) is : (B) F < Cl < Br < I (C) F < Cl > Br > I (D) Cl > Br > F > I The order of electron gain enthalpy (magnitude) of O, S and Se is : (A) O > S > Se 27. (D) IIK > IICa The first ionisation enthalpies of Na, Mg, Al and Si are in the order : (A) F > Cl > Br > I 26. (C) IICa > IIK The first ionisation enthalpies (in eV) of N & O are respectively given by : (A) 14.6, 13.6 24. (B) IK > ICa (B) S > Se > O (C) Se > S > O (D) S > O > Se Which of the following statements is/are correct ? (A) Electron gain enthalpy may be positive for some elements. (B) Second electron gain enthalpy always remains positive for all the elements. (C) egH(K+) = – IE (K) (D) All of these 28. Which of the following will have the most negative electron gain enthalpy and which the least negative ? F, P, S, Cl. (A) P, Cl 29. (B) Cl, F (C) Cl, S (D) Cl, P Electronic configurations of four elements A, B, C and D are given below : (i) 1s22s22p6 (ii) 1s22s22p4 (iii) 1s22s22p63s1 (iv) 1s22s22p5 Which of the following is the correct order of increasing tendency to gain electron : (A) (i) < (iii) < (ii) < (iv) 30. (C) (iv) < (ii) < (iii) < (i) xy 2 (B) y = xz 2 (C) x = zy 2 The electronegativity values of C,N,O and F on Pauling scale : (A) decrease from carbon to fluorine. (B) increase from carbon to fluorine. (C) increase upto oxygen and then decrease upto fluorine. (D) decrease from carbon to nitrogen and then increase continuously. 32. (D) (iv) < (i) < (ii) < (iii) If x, y and z are electronegativity on Mulliken scale, ionisation potential (in V) and electron affinity (+, in eV) respectively, then the electron affinity in the terms of electronegativity and ionisation potential will be : (A) z  31 (B) (i) < (ii) < (iii) < (iv) The correct order of electronegativity on Pauling scale is : (A) F > Cl > O > S (B) Li > Na > K > Rb > Cs (C) Be < B < N < C (D) Both (A) and (B) (D) z = 2x – y PERIODIC TABLE AND ITS PROPERTIES 33. Which of the following is affected by the stable electron configuration of an atom ? (a) Electronegativity (b) Ionisation enthalpy (c) Electron gain enthalpy Correct answer is : (A) only electronegativity (B) only ionisation enthalpy (C) only electron gain enthalpy and ionisation enthalpy (D) all of the above 34. Correct order of electronegativity of N, P, C and Si on Pauling scale is : (A) N > P > C > Si (B) C > Si > N > P (C) N < P < C < Si (D) N > C > P > Si 35. The electronegativity values of the elements are useful in predicting : (A) bond energy of a molecule. (B) polarity of a molecule. (C) nature of an oxide. (D) all of these 36. Identify the incorrect order of acidic strengths of CO2, CuO, CaO, H2O : (A) CuO < CaO < H2O < CO2 (B) H2O < CuO < CaO < CO2 (C) CaO < H2O < CuO < CO2 (D) All of these 37. Select the correct order(s) of acidic/basic strength : (A) NaOH < Mg(OH)2 < Al(OH)3 ; basic strength (C) H2SO3 < H2SO4 ; acidic strength (B) H2S > H2Se > H2Te ; acidic strength (D) Both (B) and (C) The order of basic character of given oxides is : (A) Na2O > MgO > CuO > SiO2 (C) SiO2 > MgO > CuO > Na2O (B) MgO > SiO2 > CuO > Na2O (D) CuO > Na2O > MgO > SiO2 38. 39 An element X having configuration ns2np1 occurs in a short period of Modern periodic table. The formula and nature of its oxide is : (A) XO3, amphoteric (B) XO3, acidic (C) X2O3, amphoteric (D) X2O3, basic 40. In which of the following elements, + 3 oxidation state is more stable than + 5 ? (A) P (B) As (C) N 41. Which of following does not exists : (A) TlI3 42. (D) Bi (B) PbF4 (C) Both (A) and (B) (D) None of these (C) BiI5 < BiF5 (D) Sn2+ = Ge2+ Which of the following is correct order of stability : (A) Tl3+ > Bi3+ (B) PbO2 > PbO 43. Thallium shows different oxidation states because : (A) of its high reactivity (B) of inert pair of electrons (C) of its amphoteric nature (D) its is a transition metal 44. An element has atomic number is 29. It belongs to : (A) 4th period, group 11 (C) 4th period, group II B (B) 5th period, group 10 (D) 5th period, IB group The oxidation state of nitrogen varies from: (A) –3 to + 5 (B) 0 to +5 (C) –3 to 1 45. (D) +3 to +5 46. When H2SO3 is converted into H2SO4 the change in the oxidation state of sulphur is from(A) 0 to + 2 (B) +2 to + 4 (C) +4 to +2 (D) +4 to + 6 47. The halogen that shows same oxidation state in all its compounds with other elements is(A) I2 (B) F2 (C) Cl2 (D) Br2 48. Which of the following contains atomic number of only -sblock (A) 55,12,18,53 (B) 13,33,54,83 (C) 3, 20,55,87 (D) 22,33,55,66 49. What is the atomic number of last member of the seventh period of the extended form of periodic table? (A) 116 (B) 118 (C) 120 (D) 122 50. The oxidation number and covalency of suphur in the sulphur molecule (S8) are respectively : (A) 0 and 2 (B) + 6 and 8 (C) 0 and 8 (D) +6 and 2 51. The oxidation number that iron does not exhibit in its common compounds or in its elemental state is : (A) 0 (B) +1 (C) +2 (D) +3 52. Most stable oxidation state of gold is : (A) + 1 (B) +3 53. 54. 55. 56. 57. 58. (C) +2 The most stable oxidation state of chromium is (A) +5 (B) +3 (C) +2 Which can have both +ve and –ve oxidation states? (A) F (B) I (C) Na (D) zero (D) +4 (D) He Conversion of PbSO4 to PbS the oxidation number of sulphur in PbS is(A) –2 (B) + 6 (C) +4 (D) –1 Oxidation state of oxygen in H2O2 is(A) –2 (B) –1 (C)+1 (D) +2 The oxidation number of phosphorus in Mg2P2O7 is (A) +5 (B) –5 (C) +6 (D) –7 Which metal exhibits more than one oxidation states? (A) Na (B) Mg (C) Al (D) Fe 59. The atomic number of an element which can not show the oxidation state of +3 is : (A) 13 (B) 32 (C) 33 (D)17 60. The most common oxidation state of an element is –2. The number of electrons present in its outer most shell is : (A) 2 (B) 4 (C) 6 (D) 8 61. Which of the following element shows only –1 oxidation number in combined state : (A) F (B) Cl (C) Br (D) I 62. Oxidation number of S in S2Cl2 is (A) + 1 (B) + 6 63. (C) 0 In the conversion of Br2 to BrO3–, the oxidation state of bromine changes from(A) 0 to + 5 (B) – 1 to + 5 (C) 0 to –3 (D) – 1 (D) +2 to +5 PERIODIC TABLE AND ITS PROPERTIES 64 Which of the following is true about the element 33As according to Modern periodic table : (A) It is a 5th period element. (B) It is a p-block element. th (C) It belongs to 16 group. (D) It is one among typical elements. 65. Li resembles Mg due to diagonal relationship, which is attributed to : (A) similar atomic and ionic size (B) similar electronegativity (C) similar ionization enthalpy (D) Both (A) and (B) 66. Which of the following is correct order of increasing Zeff : (A) S2– < Cl– < K+ < Ca2+ (B) S2– > Cl– > K+ > Ca2+ (C) Cl– < S2– < K+ < Ca2+ (D) S2– < Cl– < Ca2+ < K+ 67. When the following five anions are arranged in order of decreasing ionic radius, the correct sequence is : (A) Se2–, I–, Br–, O2–, F– (B) I– , Se2–, Br– , F–, O2– 2– – – – 2– (C) Se , I , Br , F , O (D) I–, Se2–, Br–, O2–, F– 68. The group in Modern periodic table, in which all the elements do not have same number of electrons in their valence shell is : (A) 13th (B) 11th (C) 9th (D) zero 69. The first element of a group differs in many ways from the other heavier members of the group. This is due to : (A) small size (B) high electronegativity and high ionisation potential (C) unavailability of d-orbitals (D) all of the above 70. Screening effect is not observed in : (A) He+ (B) Li2+ (C) Be3+ The radii of N, N3–, O and O2– are in the order : (A) N3– > O2– > O > N (C) N3– > O2– > N > O (B) O2– > N3– > N > O2– > O (D) N > O > O2– > N3– 71. 72. In which of the following compounds, manganese shows maximum radius ? (A) MnO2 (B) KMnO4 (C) MnO (D) In all cases (D) K3[Mn(CN)6] 73. The statement that is not correct for periodic classification of elements in Modern periodic table is : (A) The properties of elements are periodic function of their atomic numbers. (B) Non-metallic elements are less in number than metallic elements. (C) For transition elements, the 3d-orbitals are filled with electrons after 3p-orbitals and before 4s-orbitals. (D) The first ionisation enthalpies of elements generally increase with increase in atomic number as we go along a period. 74. Values of E1, E2 and E3 of an element are 9.3, 18.2 and 553.8 eV. What information(s) do these data convey? (A) The element has two electrons in the valence shell. (B) The element belongs to 14th group of Modern periodic table. (C) Both (A) and (B) (D) None of these 75. Which of the following is the correct order of ionisation enthalpy ? (1) Be+ > Be (2) Be > Be+ (3) C > Be (A) 2, 3 (B) 3, 4 (C) 1, 3 (4) B > Be (D) 1, 4 76. 77. Considering the elements B, Al, Mg, and K, the correct order of their metallic character is : (A) B > Al > Mg > K (B) Al > Mg > B > K (C) Mg > Al > K > B (D) K > Mg > Al > B The formation of the oxide ion, O2–(g), from oxygen atom requires first an exothermic and then an endothermic step as shown below : O(g) + e–  O–(g) ; egH = – 141 kJmol–1 O–(g) + e–  O2–(g) ; egH = + 780 kJmol–1 Thus process of formation of O2– in gas phase is unfavourable even though O2– is isoelectronic with neon. It is due to the fact that : (A) oxygen is more electronegative. (B) addition of electron in oxygen results in larger size of the ion. (C) electron repulsion outweighs the stability gained by achieving noble gas configuration. (D) O– ion has comparatively smaller size than oxygen atom. 78. Aqueous solutions of two compounds M1 – O – H and M2 – O – H are prepared in two different beakers. If, the electronegativity of M1 = 3.4, M2 = 1.2, O = 3.5 and H = 2.1, then the nature of two solutions will be respectively: (A) acidic, basic 79. (B) acidic, acidic (C) basic, acidic (D) basic, basic. Which of the following statement is incorrect ? (A) The tendency to attract bonded pair of electron in case of hybrid orbitals follow the order : sp > sp2 > sp3 (B) Alkali metals generally have negative value of electron gain enthalpy. (C) Cs+(g) releases more energy upon gain of an electron than Cl(g). (D) The electronegativity values for 2p-series elements is less than that for 3p-series elements on account of small size and high inter electronic repulsions. 80. The ground state electronic configurations of some elements, A, B, C, D, and E (these symbols represent the some of the known elements given in the Modern periodic table) are as follows : A : 1s2 2s2 2p6 3s2 3p2 B : 1s2 2s2 2p6 3s2 3p6 4s1 C : 1s2 2s2 2p6 3s2 3p1 D : 1s2 2s2 2p6 3s2 3p6 3d5 4s1 E : 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6. Match the electronic configurations of the elements with the properties given below and select the correct sequence by choosing the correct codes given. (i) Element forms a cation which is isoelectronic with P3–. (ii) Element which in its compounds can show a maximum oxidation state of +6 and also forms coloured compounds in this oxidation state. (iii) Element has largest atomic radius and highest first ionisation enthalpy in the respective period. (iv) Element which has intermediate value of electronegativity and its oxide forms salts with strong acids and bases. (A) B C E A (B) B D E C (C) B C D E (D) A B C D PERIODIC TABLE AND ITS PROPERTIES 81. Fluorine has the highest electronegativity among the ns2 np5 group on the Pauling scale, but the electron affinity of fluorine is less than that of chlorine because : (A) the atomic number of fluorine is less than that of chlorine. (B) fluorine being the first member of the family behaves in an unusual manner. (C) chlorine can accommodate an electron better than fluorine by utilising its vacant 3d–orbital. (D) small size, high electron density and an increased electron repulsion makes addition of an electron to fluorine less favourable than that in the case of chlorine in isolated stage. 82. Which of the following statement is incorrect ? (A) Oxide of aluminium (Al2O3), and arsenic (As2O3) are amphoteric. (B) Oxide of chlorine (Cl2O7) is less acidic than oxide of nitrogen (N2O5). (C) Oxide of carbon (CO2) is more acidic than oxide of silicon (SiO2). (D) The correct increasing order of basic character of various oxides is H2O < CuO < MgO < CaO. 83. Considering the elements F, Cl, O and N, the correct order of their chemical reactivity in terms of oxidizing property is : (A) F > Cl > O > N 84. 85. (B) F > O > Cl > N (C) Cl > F > O > N (D) O > F > N > Cl Strontium metaphosphate is (A) Sr (PO3)2 (B) SrHPO3 (C) Sr3(PO4)2 (D) Sr2P2O7 Nickel (II) pyroselenate is (A) Ni2Se2O7 (B) NiSe2O7 (C) Ni2Se2O5 (D) NiSe2O5 86. The formula of sodium tungstate is Na2WO4 and that of lead phosphate is Pb3(PO4)2. What is the formula for lead tungstate ? (A) PbWO4 (B) Pb2(WO4)3 (C) Pb3(WO4)2 (D) Pb3(WO4)4 87. Mercurous azide is (A) Hg2(N3)2 88. (B) HgN3 Fe[Fe(CN)6] is : (A) ferroferrocyanide (C) ferroferricyanide (C) Hg2N3 (D) Hg(N3)2 (B) Ferriferricyanide (D) ferriferrocyanide 89. Ethyl methyl ether , CH3–O–C2H5, is used as an anaesthetic . Formula for corresponding thioether would be : (A) CH3 —S—C2H5 (B) CH3—O—S—C2H5 (C) C2H5—O—CH3 (D) C2H5—O—CH2SH 90. Hydracid which contains nitrogen is : (A) HN3 (B) HNO3 (C) HNO2 (D) NH3 Anhydride of HClO4 is : (A) Cl2O7 (C) Cl2O5 (D) ClO2 91. 92. (B) ClO3 Correct name of the compound NaCrO2 will be (A) Sodium metachromate (C) Sodium orthochromate (B) Sodium metachromite (D) Sodium orthochromite 93. Which of the following acids cannot be simply converted into other acids by addition or removal of water ? (A) H3PO4 (B) HPO3 (C) H3PO3 (D) H3PO2 94. Of the following pairs, the one containing examples of metalloid elements is : (A) B and Al (B) Ga and Ge (C) Al and Si 95. 96. Which of the following is the wrong statement ? (A) All the actinide elements are radioactive. (C) Pnicogens and halogens are p-block elements. (D) As and Sb (B) Alkali and alkaline earth metals are s-block elements. (D) The first member of the lanthanide series is lanthanum. Atomic number of 15, 33, 51 represents the following family : (A) carbon family (B) nitrogen family (C) oxygen family (D) None of these 97. The places that were left empty by Mendeleev in his periodic table were for : (A) aluminium and silicon (B) gallium and germanium (C) arsenic and antimony (D) molybdenum and tungsten 98. The elements which exhibit both vertical and horizontal similarities are : (A) inert gas elements (B) representative elements (C) transition elements (D) none of these 99. According to Modern periodic table, Chalcogens are elements of : (A) group 16 (B) p-block 2 4 (C) ns np configuration (D) all of these 100. Which set does not shows correct matching according to Modern periodic table : (A) Cr = [Ar] 3d5 4s1; element belongs to 6th group. (B) Fe2+ = [Ar] 3d6; element belongs to 8th group. (C) Sc3+ = [Ne] 3s2 3p6; element belongs to zero/eighteen group. (D) All of the above. 101. In a given energy level, the order of penetration effect of different orbitals is : (A) f < p < d < s (B) s < p < d < f (C) f < d < p < s (D) s = p = d = f 102. Statement-1 : Generally in a period in Modern periodic table, noble gas has the largest atomic radius. Statement-2 : In case of noble gases, Vander waal's radius is defined and there are large inter-electronic repulsions. (A) Statement-1 is True, Statement-2 is True ; Statement-2 is a correct explanation for Statement-1. (B) Statement-1 is True, Statement-2 is True ; Statement-2 is NOT a correct explanation for Statement-1. (C) Statement-1 is True, Statement-2 is False. (D) Statement-1 is False, Statement-2 is True. (E) Statement-1 and Statement-2 both are False. 103. Statement-1 : Br– and As3– are isoelectronic but the ionic radius of As3– is greater than that of Br–. Statement-2 :The magnitude of effective nuclear charge on the outermost shell electrons in As3– is lesser than that in Br–. (A) Statement-1 is True, Statement-2 is True ; Statement-2 is a correct explanation for Statement-1. (B) Statement-1 is True, Statement-2 is True ; Statement-2 is NOT a correct explanation for Statement-1. (C) Statement-1 is True, Statement-2 is False. (D) Statement-1 is False, Statement-2 is True. (E) Statement-1 and Statement-2 both are False. 104. Which of the following statement is wrong for the d-block elements : (A) General electronic configuration for them is (n – 1)d1–10ns0–2. (B) They generally exhibit variable valency. (C) Last electron enters in (n – 1)d subshell in them. (D) They are placed from 3rd to 6th period in modern periodic table. PERIODIC TABLE AND ITS PROPERTIES 105. In which element shielding effect is not possible ? (A) H (B) Be (C) B (D) N 106. Which of the following gaseous atoms has highest value of ionisation enthalpy ? (A) P (B) Si (C) Mg (D) Al 107. The second ionization enthalpies of elements are always higher than their first ionization enthalpies because: (A) cation formed always have stable half filled or completely filled valence shell electron configuration. (B) it is easier to remove electron from cation. (C) ionization is an endothermic process. (D) the cation is smaller than its parent atom. 108. A large difference between the third and fourth ionization energies indicates the presence of : (A) 4 valence electrons in an atom (B) 5 valence electrons in an atom (C) 3 valence electrons in an atom (D) 2 valence electrons in an atom 109. Which of the following is the correct order of ionisation enthalpy ? (A) Te2– < I– < Cs+ < Ba2+ (B) I– < Te2– < Cs+ < Ba2+ (C) Te2– < Cs+ < I– < Ba2+ (D) Ba2+ < Cs+ < I– < Te2– 110. The correct order of electron gain enthalpy (most endothermic first and most exothermic last) is : (A) Be < B < C < N (B) Be < N < B < C (C) N < Be < C < B (D) N < C < B < Be 111. For magnitude of electron gain enthalpy of chalcogens and halogens, which of the following options is correct ? (A) Br > F (B) S > F (C) O < Cl (D) S < Se 112. The lanthanide contraction refers to : (A) radius of the series. (C) the density of the series. (B) valence electrons of the series. (D) electronegativity of the series. 113. Select correct statement(s) : (A) Across a transition series (from Cr to Cu), there is only a small change in atomic radius from one element to another due to very small change in effective nuclear charge. (B) The rate of decrease in the size across the lanthanide series is less than the across the first transition series. (C) Both are correct statements. (D) None of the statement is correct. 114. Which is/are true statement(s) ? (A) Larger is the value of ionisation enthalpy, easier is the formation of cation. (B) Larger is the value of electron gain enthalpy, easier is the formation of anion. (C) Larger is the value of ionisation energy as well as electron affinity, smaller is the Mulliken electronegativity of atom. (D) Larger is the Zeff, larger is the size of atom. 115. Which of following ions do not exist together in aqueous solution : (A) Pb2+, F– (B) Tl3+, I– (C) Both (A) and (B) (D) None of these 116. Increasing order of acidic character is : (A) SO3 > N2O5 > CO2 > SiO2 (C) SO3 < N2O5 > CO2 < SiO2 (B) SO3 < N2O5 (D) SO3 > N2O5 Amphoteric behaviour is shown by the oxides of : (A) Al and Ca (B) Pb and N (C) Be and B 117. 118. < CO2 < SiO2 > CO2 < SiO2 (D) Sn and Zn Which one of the following statements is correct ? (A) The elements having large negative values of electron gain enthalpy generally act as strong oxidising agents. (B) The elements having low values of ionisation enthalpies act as strong reducing agents. (C) The formation of S2–(g) from S(g) is an endothermic process. (D) All of these. EXERCISE - 1 1. D 14. C 27. D 40. D 53. B 66. A 79. D 92. B 105. A 118. D 2. C 15. C 28. D 41. D 54. B 67. D 80. B 93. C 106. A 3. B 16. B 29. A 42. C 55. A 68. D 81. D 94. D 107. D 4. C 17. A 30. D 43. B 56. B 69. D 82. B 95. D 108. C 5. C 18. B 31 B 44. A 57. A 70. D 83. A 96. B 109. A 6. C 19. D 32. B 45. A 58. D 71. C 84. A 97. B 110. B 7. D 20. A 33. C 46. D 59. B 72. C 85. B 98. C 111. C 8. D 21. C 34. D 47. B 60. C 73. C 86. A 99. D 112.A 9. D 22. D 35. D 48. C 61. A 74. A 87. A 100. C 113.C 10. D 23. A 36. D 49. B 62. A 75. C 88. B 101. C 114. B 11. A 24. A 37. C 50. A 63. A 76. D 89. A 102. A 115.B 12. D 25. C 38. A 51. B 64 B 77. C 90. A 103. A 116.A 13. D 26. B 39 C 52. D 65. D 78. A 91. A 104. D 117.D