alleryFilling 4f before 5d causes a steady fall in radii called:
ALanthanoid contraction
BActinoid contraction
CTransition expansion
DPeripheral extension
Answer & Solution
Correct answer: A. Lanthanoid contraction
1. The 4f orbitals fill before the 5d series begins.
2. That filling shrinks the atoms regularly.
3. The effect is called the lanthanoid contraction.
_Source: syllabus Chemistry Part I, Chapter 8, The d- and f-Block Elements._
Keep practising The d- and f-Block Elements
Browse all The d- and f-Block Elements questions for CBSE Class 12 (Science), or explore more Chemistry topics.
Related questions
Metals that readily form homogeneous alloys have radii within aboutMany copper(I) compounds in aqueous solution undergoSubstances that are attracted very strongly by a magnetic field are calledThe spin-only magnetic moment of Mn2+ (five unpaired electrons) is nearlyParamagnetism in transition metal ions arises from the presence ofTransition metals form many complexes owing to small ions, high charge andInterstitial compounds of transition metals are chemicallyCompounds formed when small atoms like H, C or N sit inside metal lattices are