Question

The screening effect of d-electrons is

• A. Equal to p-electrons
• B. Much more than p-electrons
• C. Same as f-electrons
• D. Less than p-electrons.

Hint:

Remember the order \(s \textgreater p \textgreater d \textgreater f\). Poor shielding by d and f electrons is responsible for phenomena like Lanthanide contraction and the inert pair effect.

Answer 1

The Correct Option is D

Step 1: Understanding the Question:
The question compares the shielding (screening) ability of electrons in different subshells within the same principle energy level.

Step 2: Detailed Explanation:
The screening effect depends on the shape and penetration of the orbitals.
- s-orbitals are spherical and penetrate closest to the nucleus, providing the maximum screening.
- p-orbitals have a dumb-bell shape and slightly less penetration.
- d and f orbitals have more diffused shapes and poor penetration, leading to poor screening of nuclear charge.
The order of screening effect for a given shell is: \(s \textgreater p \textgreater d \textgreater f\).
Therefore, d-electrons provide less screening than p-electrons.

Step 3: Final Answer:
The screening effect of d-electrons is less than p-electrons.