Question:

Which of the following factors may be regarded as the main cause of lanthanide contraction ?

Updated On: Aug 1, 2022
  • Greater shielding of 5d electron by 4f electrons
  • Poorer shielding of 5d electron by 4f electrons
  • Effective shielding of one of 4f electrons by another in the sub-shell
  • Poor shielding of one of 4f electron by another in the sub-shell
Hide Solution
collegedunia
Verified By Collegedunia

The Correct Option is D

Solution and Explanation

Lanthanide contraction is due to poor shielding of one of 4f electron by another in the sub-shell.
Was this answer helpful?
0
0

Concepts Used:

D and F Block Elements

The d-block elements are placed in groups 3-12 and F-block elements with 4f and 5f orbital filled progressively. The general electronic configuration of d block elements and f- block elements are (n-1) d 1-10 ns 1-2 and (n-2) f 1-14 (n-1) d1 ns2 respectively. They are commonly known as transition elements because they exhibit multiple oxidation states because of the d-d transition which is possible by the availability of vacant d orbitals in these elements. 

They have variable Oxidation States as well as are good catalysts because they provide a large surface area for the absorption of reaction. They show variable oxidation states to form intermediate with reactants easily. They are mostly lanthanoids and show lanthanoid contraction. Since differentiating electrons enter in an anti-penultimate f subshell. Therefore, these elements are also called inner transition elements.

Read More: The d and f block elements