Q. Lanthanide contraction is due to increase in
A) Shielding by $4f$-electrons
B) Atomic number
C) Effective nuclear charge
D) Size of $4f$-orbitals
Explanation
(c)
Lanthanide contraction is due to the imperfect shielding of $f$-electrons due to the diffused shape of $f$-orbitals. Therefore, as the atomic number increases effective nuclear charge increases and this results in contraction of size of the 4$f$-subshell.”
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.