Question

What is the total number of transition series of d-block elements?

• A. \(3\)
• B. \(4\)
• C. \(10\)
• D. \(12\)

Hint:

The d-block contains the 3d, 4d, 5d and 6d series.

Answer 1

The Correct Option is B

Step 1: Count by period:
The d-block starts at period 4 and continues through periods 5, 6 and 7.

Step 2: Total:
That is $4$ rows: $3d$, $4d$, $5d$ and $6d$.

Final Answer:
The number of series is $4$, option (B). \[ \boxed{4} \]