Join the Most Relevant JEE Main 2025 Test Series & get 99+ percentile! Join Now
Search any question & find its solution
Question: Answered & Verified by Expert
In $f$-block elements, orbitals are progressively filled by the electrons.
ChemistryStructure of AtomAP EAMCETAP EAMCET 2021 (23 Aug Shift 2)
Options:
  • A $3 f$ and $4 f$
  • B $4 f$ and $5 f$
  • C $5 f$ and $6 f$
  • D $6 f$ and $7 f$
Solution:
2270 Upvotes Verified Answer
The correct answer is: $4 f$ and $5 f$
The general electronic configuration of $f$-block elements is
$(n-2) f^{(0-14)}(n-1) d^{(0-1)} n s^2$
General electronic configuration of
lanthanoids is [Xe] $4 f^{1-14} 5 d^{0-1} 6 s^2$
and actinoides is $[\mathrm{Rn}] 5 f^{1-14} 6 d^{0-1} 7 s^2$
So, $4 f$ and $5 f$ orbitals are filled in $f$-block elements.

Looking for more such questions to practice?

Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.