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NEETChemistryd and f Block Elements

What is the main reason for the irregularity in lanthanoid ionization enthalpies?

Options

  1. AThe presence of extra stability in the f subshell
  2. BThe absence of stability in the d subshell
  3. CThe variation in the number of s electrons
  4. DThe strong reducing agent properties of lanthanoids

Correct answer

A. The presence of extra stability in the f subshell

Step-by-step solution

The irregularity in ionization enthalpies arises from the extra stability of empty, half-filled, or filled f subshell.

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