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

Gujarat BoardEnglish MediumSTD 12 ScienceChemistryThe d & f Block Elements1 Mark
MCQ
The atomic and ionic radii (M3+ ions) of Lanthanide elements decrease with increase in atomic number. This effect is called as:
  • A
    Lanthanoid contraction.
  • B
    Lanthanoid expansion.
  • C
    Actinoid contraction.
  • D
    None of these.
✓

Answer

  1. Lanthanoid contraction.

Explanation:

The atomic and ionic radii (M3+ ions) of Lanthanide elements decrease with increase in atomic number.

This effect is called Lanthanoid contraction. This is due to poor shielding of f electrons.

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