Identify the block to which an element with electronic configuration: `[Kr]4d^(10)4f^(14)5s^2 5p^6 5d^1 6s^2` belongs to 

Options

A. s-block
B. p-block
C. d-block
D. f-block

Answer

To identify the block to which the element with the electronic configuration `[Kr]4d^(10)4f^(14)5s^2 5p^6 5d^1 6s^2` belongs, we will analyze the outermost electrons in the configuration step by step.

### Step-by-Step Solution:

1. **Identify the outermost shell**:
The highest principal quantum number (n) in the given electronic configuration is 6. Therefore, the outermost shell is n=6.

2. **List the electrons in the outermost shell**:
The outermost electrons in the configuration are:
- 6s² (2 electrons)
- 5d¹ (1 electron)

3. **Determine the filled subshells**:
The configuration also includes filled subshells:
- 4f¹⁴ (14 electrons)
- 5s² (2 electrons)
- 5p⁶ (6 electrons)
- 4d¹⁰ (10 electrons)

4. **Identify the block based on the outermost electrons**:
The outermost electrons are in the 6s and 5d subshells. The presence of the 5d subshell indicates that this element is likely in the d-block. However, since we also have electrons in the 4f subshell, we need to consider the f-block as well.

5. **General electronic configuration for f-block elements**:
The general electronic configuration for f-block elements is:
- (n-2)f¹⁴ (for lanthanides and actinides)
- (n-1)d¹⁰ (for transition metals)
- ns² (for s-block)

In this case, we have:
- 4f¹⁴ (n-2, where n=6)
- 5d¹ (n-1)
- 6s² (ns)

6. **Conclusion**:
Since the configuration includes filled f-orbitals (4f¹⁴) and the presence of d and s electrons, we conclude that the element belongs to the f-block of the periodic table.

### Final Answer:
The element with the electronic configuration `[Kr]4d^(10)4f^(14)5s^2 5p^6 5d^1 6s^2` belongs to the **f-block** of the periodic table.