An element has electronic configuration [Xe] `4f^(7), 5d^(1),6s^(2)`. It belongs to ____ block of this periodic table.

Options

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

Answer

To determine the block of the periodic table to which the element with the electronic configuration [Xe] 4f^7 5d^1 6s^2 belongs, we can follow these steps:

### Step 1: Analyze the Electronic Configuration
The given electronic configuration is [Xe] 4f^7 5d^1 6s^2. Here, we can break it down into its components:
- [Xe] represents the core electrons, which are not involved in bonding.
- 4f^7 indicates that there are 7 electrons in the 4f subshell.
- 5d^1 indicates that there is 1 electron in the 5d subshell.
- 6s^2 indicates that there are 2 electrons in the 6s subshell.

### Step 2: Identify the Highest Energy Subshell
The block of the periodic table is determined by the highest energy subshell that contains electrons. In this case:
- The highest energy subshell is 4f, as it has electrons (4f^7).
- The presence of 5d and 6s electrons does not change the fact that the 4f subshell is the highest occupied subshell.

### Step 3: Determine the Block
The periodic table is divided into four blocks based on the subshells:
- s-block: Groups 1 and 2 (and Helium)
- p-block: Groups 13 to 18
- d-block: Transition metals (Groups 3 to 12)
- f-block: Lanthanides and actinides

Since the highest energy subshell with electrons is 4f, this element belongs to the f-block of the periodic table.

### Conclusion
Thus, the element with the electronic configuration [Xe] 4f^7 5d^1 6s^2 belongs to the **f-block** of the periodic table.

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