Periodic Table and Its Properties Exercise # 3

PERIODIC TABLE AND ITS PROPERTIES Exercise # 3 Part # I [Matrix Match Type Questions] 1. Match the electronic configurations of the elements given in column-(I) with their correct characteristic(s) ( i.e. properties for given configuration) given in column-(II). Column-I Column-II 2 (A) 1s (p) Element shows highest negative oxidation state. 2 2 5 (B) 1s 2s 2p (q) Element shows highest first ionisation enthalpy. (C) 1s2 2s2 2p6 3s2 3p5 (r) Element shows highest electronegativity on Pauling scale. 2 2 2 (D) 1s 2s 2p (s) Element shows maximum electron gain enthalpy (most exothermic). 2. Match Column–I (atomic number of elements) withColumn–II (position of element in periodic table) and select the correct answer using the codes given below : Column-I Column-II (A) 19 (p) p-block (B) 22 (q) f-block (C) 32 (r) d-block (D) 64 (s) s-block 3. Column-I (A) Increasing ionisation potential (B) Increasing electronegativity (C) Decreasing Zeff (D) Decreasing electron affinity 4. Match Column–I (Elements) withColumn–II (configuration of elements) and select the correct answer using the codes given below : Column-I Column-II (A) The third alkali metal (p) 1s2 2s2 2p6 3s2 3p5 (B) The second transition element (q) 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 (C) The fourth noble gas element (r) 1s2 2s2 2p6 3s2 3p6 3d2 4s2 (D) The second helogen element (s) 1s2 2s2 2p6 3s2 3p6 4s1 5. Column-I (A) Increasing atomic size (B) Decreasing atomic radius (C) Increasing electronegativity (D) Increasing effective nuclear charge Column-II (p) Cl < O < F (q) Li < Be < B (r) Si < Al < Mg (s) N > O > F 6. Column-I (A) Metalloid (B) Radioactive (C) Transition (D) Chalcogen Column-II (p) Selenium (q) Silver (r) Arsenic (s) Uranium Column-II (p) N > O > F (q) N < O < F (r) O < N < F (s) O > C > N Part # II [Comprehension Type Questions] Comprehension # 1 1. 2. 3. 4. Ionization energies of five elements in kcal/mol are given below : Atom I II P 300 549 Q 99 734 R 118 1091 S 176 347 T 497 947 III 920 1100 1652 1848 1500 Which element is a noble gas ? (A) P (B) T (C) R (D) S Which element form stable unipositive ion : (A) P (B) Q (C) R (D) S The element having most stable oxidation state +2 is : (A) Q (B) R (C) S (D) T Which is a non-metal (excluding noble gas) : (A) P (B) Q (D) S (C) R 5. If Q reacts with fluorine and oxygen, the molecular formula of fluoride and oxide will be respectively : (A) QF3, Q2O3 (B) QF, Q2O (C) QF2, QO (D) None of these 6. Which of the following pair represents elements of same group : (A) Q, R (B) P, Q (C) P, S (D) Q, S Comprehension # 2 Four elements P,Q,R & S have ground state electronic configuration as : P 1s2 2s2 2p6 3s2 3p3 Q 1s2 2s2 2p6 3s2 3p1 R 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p3 1. 2. S 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p1 Which of the following option represent the correct order of true (T) and False (F) Statement: I. size of P< size of Q II. size of R < size of S III. size of P < size of R (appreciable difference) IV. size of Q < size of S (appreciable difference) (A) TTTT (C) FFTT (D) TTFF (C) R > S > P > Q (D) P > S > R > Q (B) TTTF Order of IE1 values among the following is : (A) P > R > S > Q (B) P < R < S < Q Comprehension # 3 In the modern periodic table, elements are arranged in order of increasing atomic numbers which is related to the electronic configuration. Depending upon the type of orbitals receiving the last electron, the elements in the periodic table have been divided into four blocks, viz, s, p, d and f. The modern periodic table consists of 7 periods and 18 groups. Each period begins with the filling of a new energy shell. In accordance with the Arfbau principle, the seven periods (1 to 7) have 2, 8, 8, 18, 18, 32 and 32 elements respectively. The seventh period is still incomplete. To avoid the periodic table being too long, the two series of f-block elements, called lanthanoids and actinoids are placed at the bottom of the main body of the periodic table. PERIODIC TABLE AND ITS PROPERTIES Now answer the following five questions : 1. The element with atomic number 57 belongs to : (A) s-block 2. (C) d-block (D) f-block The last element of the p-block in 6th period is represented by the outermost electronic configuration : (A) 7s27p6 3. (B) p-block (B) 5f146d107s27p0 (C) 4f145d106s26p6 (D) 4f145d106s26p4 Which of the elements, whose atomic numbers are given below, cannot be accommodated in the present set up of the long form of the periodic table ? (A) 107 4. (B) 118 (C) 126 (D) 102 The electronic configuration of the element which is just above the element with atomic number 43 in the same group is ________: 5. (A) 1s22s22p63s23p63d54s2 (B) 1s22s22p63s23p63d54s34p6 (C) 1s22s22p63s23p63d64s2 (D) 1s22s22p63s23p63d74s2 The elements with atomic numbers 35, 53 and 85 are all ________ : (A) noble gases (B) halogens (C) heavy metals (D) light metals Comprehension # 4 It is not possible to measure the atomic radius precisely since the electron cloud surrounding the atom does not have a sharp boundary. One practical approach to estimate the size of an atom of a non-metallic element is to measure the distance between two atoms when they are bound together by a single bond in a covalent molecule and then dividing by two. For metals we define the term “metallic radius” which is taken as half the internuclear distance separating the metal cores in the metallic crystal. The van der waal’s radius represents the over all size of the atoms which includes its valence shell in a non bonded situation. It is the half of the distance between two similar atoms in separate molecules in a solid. The atomic radius decreases across a period and increases down the group. Same trends are observed in case of ionic radius. Ionic radius of the species having same number of electrons depends on the number of protons in their nuclei. Sometimes, atomic and ionic radii give unexpected trends due to poor shielding of nuclear charge by d- and f-orbital electrons. Now answer the following three questions : 1. 2. 3. Which of the following relations is correct, if considered for the same element : (A) rVanderwaal > rCovalent > rMetallic (B) rCovalent > rMetallic > r Vanderwaal (C) r Vanderwaal > rMetallic > r Covalent (D) rMetallic > rCovalent > rVanderwaal K+, CI– , Ca2+ , S2– ions are isoelectronic. The decreasing order of their size is : (A) Ca2+ > K+ > Cl– > S2– (B) S2– > Cl– > K+ > Ca2+ (C) K+ > Cl– > Ca2+ > S2– (D) S2– > Cl– > Ca2+ > K+ Select the INCORRECT option regarding atomic/ionic sizes : (A) Zn > Cu (B) Pb2+ > Pb4+ (C) Zr  Hf (D) N3– < Al3+ Comprehension # 5 The periodicity is related to the electronic configuration. That is, all chemical and physical properties are a manifestation of the electronic configuration of the elements. The atomic and ionic radii generally decrease in a period from left to right. As a consequence, the ionization enthalpies generally increase and electron gain enthalpies become more negative across a period. In other words, the ionization enthalpy of the extreme left element in a period is the least and the electron gain enthalpy of the element on the extreme right is the highest negative. This results into high chemical reactivity at the two extremes and the lowest in the centre. Similarly down the group, the increase in atomic and ionic radii result in gradual decrease in ionization enthalpies and a regular decrease (with exception in some third period elements) in electron gain enthalpies in the case of main group elements. The loss and gain of electrons can be co-related with the reducing and oxidising behaviour, and also with metallic and non-metallic character respectively, of the elements. 1. The correct order of the metallic character is : (A) Al > Mg > Na > Si (B) Na > Mg < Al > Si (C) Na > Mg > Al > Si (D) Al > Mg > Si > Na 2. Considering the elements B, C, N, F, and Si, the correct order of their non-metallic character is : (A) B > C > Si > N > F (B) Si > C > B > N > F (C) F > N > C > B > Si (D) F > N > C > Si > B 3. Which of the following statement is correct ? (A) Ionisation enthalpies of elements decrease along a period and increase along a group in Modern periodic table. (B) In the 3rd period of Modern periodic table, the two most reactive elements are sodium and fluorine. (C) Fluorine has the least negative electron gain enthalpy among all halogens. (D) Ionisation enthalpy of Pb is greater than that of Sn. EXERCISE - 3 : PART # I 1. A (q), B (r), C (s), D (p) 2. A (s), B (r), C (p), D (q) 3. A (r), B (q), C (p), D (s) 4. A (s), B (r), C (q), D (p) 5. A (r), B (s), C (p), D (q) 6. A (r), B (s), C (q), D (p) PART # II Comprehension # 1 : Comprehension # 2 : 1. 1. B B 2. 2. B,C A 3. C 4. A 5. B Comprehension # 3 : 1. C 2. C, 3. C 4. A 5. B Comprehension # 4 : 1. C 2. B 3. D Comprehension # 5 : 1. C 2. C 3. D 6. A