Q. Lanthanide contraction is caused due to
A) The appreciable shielding on outer electrons by $4f$-electrons from the nuclear charge.
B) The appreciable shielding on outer electrons by $5d$-electrons from the nuclear charge.
C) The same effective nuclear charge from Ce to Lu.
D) The imperfect shielding on outer electrons by $4f$-electrons from the nuclear charge.
Explanation
(d)
Lanthanoid contraction is due to ineffective shielding produced by larger $f$-subshell.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.