NEETChemistryd and f Block Elements
Which of the following statement is correct. (A) In Lanthanide series metallic radius regularly decreases from La to Lu . (B) La is actually an elements of transition series rather than lanthanide. (C) ( La ( OH )₃ ) is less basic than ( Lu ( OH )₃ ) (D) The atomic radius of Zr & Hf are nearly similar because of lanthanoid contraction.
Options
- AIf A, B and C options are correct.
- BIf A & B both options are correct.
- CIf A & D both are options correct.
- DIf A & C both are options correct.
Correct answer
C. If A & D both are options correct.
Step-by-step solution
(A) Correct. In the Lanthanide series, the metallic radius decreases from La to Lu due to the lanthanide contraction, which is caused by the poor shielding of the nuclear charge by the (4 f ) electrons. (B) Incorrect. Lanthanum (La) is considered a member of the Lanthanide series, not the transition series. (C) Incorrect. ( La ( OH )₃ ) is more basic than ( Lu ( OH )₃ ) because the basicity increases with the decrease in size of the metal ion. (D) Correct. The atomic radii of Zr and Hf are nearly similar due to the