Question

What is the general electronic configuration for 2nd row transition series?

• A. [Ne]3d\(^{1-10}\),4s\(^2\)
• B. [Ar]3d\(^{1-10}\),4s\(^{1-2}\)
• C. [Kr]4d\(^{1-10}\),5s\(^{1-2}\)
• D. [Xe]5d\(^{1-10}\),5s\(^{1-2}\)

Hint:

1st row: 3d, 2nd row: 4d, 3rd row: 5d.

Answer 1

The Correct Option is C

The second row transition series consists of elements from zirconium (Zr) to cadmium (Cd), encompassing atomic numbers 40 to 48. These elements are part of the d-block of the periodic table and are found in the 5th period. The electronic configuration of these elements relates to their position in the periodic table and involves filling the 4d and 5s orbitals.

The general electronic configuration for this series is:

\([Kr]\,4d^{1-10},5s^{1-2}\),

where \([Kr]\) represents the electron configuration of krypton, the nearest noble gas preceding this series.

1. Explanation: Each element in the second row transition metals builds upon the electron configuration of the previous one by adding electrons mainly to the 4d subshell. The 5s subshell is typically filled first (with 1 or 2 electrons) before the 4d begins to fill, although exceptions may arise due to stability factors.
2. Comparison to Incorrect Options:
   • \([Ne]3d^{1-10},4s^2\): This configuration pertains to the first transition series (3d transition metals), starting from scandium (Sc).
   • \([Ar]3d^{1-10},4s^{1-2}\): Also related to the first transition series.
   • \([Xe]5d^{1-10},5s^{1-2}\): Related to the third transition series (5d transition metals), starting from lanthanum (La).

Thus, the correct general electronic configuration for the second row transition series is \([Kr]4d^{1-10},5s^{1-2}\).