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The d & f Block Elements — Chemistry STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 ScienceChemistryThe d & f Block Elements3 Marks
Question
  1. Write the electronic configuration of the element with atomic number $102$.
  2. What is lanthanoid contraction? What is its effect on the chemistry of the elements which follow the lanthanoids?
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Answer

  1. $[Rn] 5f^{14}7s^2$.
  2. The steady decrease in atomic size of lanthanoids with increase in atomic number due to filling of electrons in inner orbitals.
Due to lanthanoid contraction the properties of 4d & 5d series elements become nearly same.

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