Question

Which of the following series of transition elements has general electronic configuration, \([\text{Kr}]\,4d^{1-10}\,5s^{0-2}\)?

• A. 3d series elements
• B. 4d series elements
• C. 5d series elements
• D. 6d series elements

Hint:

Krypton core followed by 4d means the second transition series.

Answer 1

The Correct Option is B

Step 1: Match the core
The core \([Kr]\) ends at atomic number \(36\), and filling \(4d\) with \(5s\) is the second row of d-block elements (\(Y\) to \(Cd\)). So this is the 4d series.

Step 2: Other series
The 3d series is \([Ar]3d^{1-10}4s^{0-2}\), the 5d series is \([Xe]4f^{14}5d^{1-10}6s^{0-2}\) and the 6d series uses \([Rn]\).

Final Answer:
It is the 4d series. \[ \boxed{\text{(B)}\ \text{4d series elements}} \]