JEE Main & Advanced Chemistry The d-and f-Block Elements / d तथा f ब्लॉक के तत्व Question Bank Critical Thinking

  • question_answer
    General configuration of outermost and penultimate shell is \[(n-1)\,{{s}^{2}}\,(n-1)\,\,{{p}^{6}}(n-1)\,\,{{d}^{x}}n{{s}^{2}}.\] If n = 4 and x = 5 then no. of proton in the nucleus will be   [MP PET 2003]

    A) > 25

    B) < 24

    C) 25

    D) 30

    Correct Answer: C

    Solution :

    Given n = 4 x = 5 So \[\underset{3{{s}^{2}}}{\mathop{(4-1){{s}^{2}}}}\,\underset{3{{p}^{6}}}{\mathop{(4-1){{p}^{6}}}}\,\underset{3{{d}^{5}}}{\mathop{(4-1){{d}^{5}}}}\,\underset{4{{s}^{2}}}{\mathop{4{{s}^{2}}}}\,\] Total electron = 2 + 6 + 5 + 2 = 15 Electron in 1 + 2 orbit = 2 + 8 = 10 Total electron = 10 + 15 = 25 No. of electron = No. of proton So total proton = 25


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