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SUBJECT: CHEMISTRY, , PERIODIC TABLE, , DAY – 3, , Q.1) Can an element with atomic number 126, if discovered, be accommodated in the present long, from of periodic table?, Q.2) Third period of the periodic table contains 8 and not 18 elements. Justify, Q.3) If scientist succeed in obtaining element with atomic number 114, which well known element, would you expect it to resemble?, Q.4) The diagram below shows part of the skeleton of the periodic table in which element are, indicated by letter which are not their usual symbols:, , Answer the following on the basis of periodic table:, (I) Alkali metal(s), (II) An element with outer configuration of d8s2, (III) Lanthanoids, (IV) Representative elements(s), (V) Elements with incomplete f-subshell, (VI) Halogen (s), (VII) s-block element(s), (VIII) Transition element (s), (IX) Noble gase (s), (X) Non-transition element (s), , Q.5) Elements A,B,C,D and E have the following electronic configurations:
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A :1s 2 2s 2 2 p1, , B :1s 2 2s 2 2 p 6 3s 2 3 p1 C :1s 2 2s 2 2 p 6 3s 2 3 p 3, , D :1s 2 2s 2 2 p 6 3s 2 3 p 5, , E :1s 2 2s 2 2 p 6 3s 2 3 p 6 4s 2, , Which among these will belong to the same group in the periodic table?, Q.6) An element X with Z=112 has been recently discovered. What is the electronic configuration of, the element? To which group and period will it belong?, Q.7) The atom having the valence shell electronic configuration 4s24p2 would be in, (A) Group II A and period 3, (B) Group II B and period 4, (C) Group IV A and period 4, (D) Group IV A and period 3, Q.8) The electronic configuration of transition elements is exhibited by, (A) ns0-2(n-1)d1-10, (B) ns2 (n-1) d10, 10 2, (C) (n-1)d s, (D) ns2np5, Q.9) Configuration of Br- is: [Ar] 3d10 4s24p6. The electronic configuration of Br+2 would be identical, with the element:, (A) Se, (B) As, (C) Ga, (D) Ge, Q.10) 4d35s2 configuration belongs to which group:, (A) IIA, (B) IIB, , (C) V B, , (D) III B, , Q.11) Which of the following electronic configurations in the outermost shell is characteristic of, alkali metals:, (A) (n-1) s2p6ns2p1, (B) (n-1) s2p6d10ns1, (C) (n-1)s2p6ns1, (D) ns2np6(n-1)d10, Q.12) Which of the following statement is false:, (A) Elements of ns2np6 electronic configuration lies in 1st to 6th period, (B) Typical elements lies in 3rd period, (C) The seventh period will accommodate thirty two elements, (D) Boron and silicon are diagonally related, Q.13) In the third period Na to Cl seven element is/are called:, (A) Lanthanides (B) Typical elements (C) Halogen elements, Q.14) In born atom Screening is due to:, (A) Electrons of K shell only, (C) Two electrons of 1s and 2s each, , (D) Metalloids, , (B) All the electrons of K and L shell, (D) Only by electrons of L shell, , Q.15) If the atomic number of an element is 58, it will be placed in the periodic table in the :, (A) III B gp and 6th period, (B) IV B gp and 6th period, th, (C) VB gp and 7 period, (D) None of the above, Q.16) If there were 10 periods in the periodic table then how many elements would this period can, maximum comprise of, (A) 50, (B) 72, (C) 32, (D) 98
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Solutions, Q.1) No. because there no provision for filing of g-block element in periodic table, Q.2) The no. of elements in a period is equal to the no. of orbitals filled in 2nd period – 2s and 2p, orbitals are filled so 8 elements are filled, Q.3) 14th group, carbon family, Q.4) (i) B, (ii) H, (iii) A, (iv) B, C, F, J, I, (v) A, (vi) I, (vii) B, J (viii) E, H, K (ix) G (x) L, Q.5) Out of theses, elements A and B will belong to the same group of the periodic table because, they have same outer electronic configuration, ns2 np1, Q.6) (a) The electronic configuration of element X is [Rn]86 5f14 6d10 7s2, (b) It belongs to d-block as last electron enters in d subshell, (c) As number of electrons in (n-1) d subshell and valence shell is equal to twelve i.e. 10 + 2., So it belongs to group 12, (d) It belongs to period 7 of the periodic table as principal quantum number of valence shell is 7, (i.e., 7s2), Q.7) C, Q.8) A, Q.9) B, Q.10) C, Q.11) C, Q.12) A, Q.13) B, Q.14) C, Q.15) A, Q.16) B
