Question

Total number of elements are in d-block is __________.

• A. 39
• B. 40
• C. 38
• D. 36

Hint:

Each transition series contains 10 elements because d-subshell can hold a maximum of 10 electrons.

Answer 1

The Correct Option is B

The question requires us to determine the total number of elements present in the d-block of the periodic table. Let's explore this step-by-step!

Understanding the d-block:

• The elements in the periodic table are classified into s-block, p-block, d-block, and f-block based on their electron configurations.
• The d-block elements are those in which the last electron enters the d subshell (n-1)d. Therefore, they are also called transition metals.
• These elements are located in the center of the periodic table, specifically in groups 3 to 12.

Counting the d-block elements:

• The d-block contains four full rows of transition metals.
• There are 10 elements in each row because the d subshell can hold a maximum of 10 electrons (5 orbitals, each with 2 electrons).
• Thus, we calculate the total count as the number of rows multiplied by elements per row:

\(4 \, \text{(rows)} \times 10 \, \text{(elements per row)} = 40\)

Conclusion:

• Therefore, the total number of elements in the d-block of the periodic table is 40.

This matches with the provided option 40, confirming it as the correct answer.