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

Gujarat BoardEnglish MediumSTD 12 ScienceChemistryThe d & f Block Elements5 Marks
Question
  1. Why do transition elements show variable oxidation states?
  1. Name the element showing maximum number of oxidation states among the first series of transition metals form Sc (Z=21) to Zn (Z=30).
  2. Name the element which shows only +3 oxidation state.
  1. What is lanthanoid contraction? Name an important alloy which contains some of the lanthanoid metals.
✓

Answer

  1. Because of incomplete filling of d-orbitals.
  1. Mn.
  2. Scandium (Sc).
  1. There is a steady decrease in the size of atoms/ions with increase in atomic number in lanthanoid. Misch metal.

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