InterviewSolution
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InterviewSolution
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Rohan was told that sixelements A,B, C,D,E and F have atomic numbers of 2,12,20,18,4 and 10 respectively (where A,B,C,D,E and F are not the chemical symbols of these elements). Based on this information, Rohan was asked to answer the following questions: (a) Which of these elements belong to the same groups of the periodic table? Why? (b) Which of these element belong tothe same periods of the periodic table? Why? (c) Which of these elements are (i) metals, and (ii) non-metals? (d) Which of these elements are chemically (i) reactive and (ii) unreactive? (e) What values are displayed by Rohan in answering the above questions? |
Answer» SOLUTION :First of allRohan wrote down the electronic configurations of all the given six elements as FOLLOWS:  (a) (i) Elements `B(2,8,2),C(2,8,8,2)` and `E(2,2)` belong to the same group (group 2) of the periodic table because all of them have an equal number of 2 valence electrons. (Element A has also 2 valence electronsbut these 2 electrons are in its only electrons shell `K` shell, so it does not belong to group 2). (ii) Elements `A(2),D(2,8,8)` and `F(2,8)` also belong to the same group (group 18) because they are all inert gases having completely filled outermost electron shells WITH8 valence electrons (except element A which has 2valence electrons in its only shell, `K` shell). (b) (i) Element `B(2,8,2)` and element `D(2,8,8)` belong to the same period (3rd period) because they both have 3 electron shells (`K,L` and `K` shells) each. (ii) Element `E(2,2)` and element `F(2,8)` belong to the same period (2nd period) because they both have 2 electron shells (`K` and `L` shells) each. (c) (i) Element B,C and E belonging to group 2 are metals. (ii) Elements A,D and F belonging to group 18 are non-metals. (d) (i) Element B,C and E of group 2 are chemically reactive because they have 2 valence electrons each which they can lose to react with other elements. (ii)Elements A,D and F of group 18 are chemically unreactive because their atoms have completely filled valence shells. They can neither lose electrons nor gain electrons or share electrons to react with other elements. (e) The various values displayed by Rohan in answering these QUESTIONS are (i) Awareness (that in modern periodic classification the elements are arrangedaccording to their electronic configuration (ii) Knowledge (to correlate the properties of elements to their electronic configurations) and (iii) Ability of apply knowledge in solving problems. |
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