The inner transition elements are the elements which the added electrons go to

Options

A. `(n-1)` d-orbitals
B. `(n-2)` f-orbitals
C. `(n-1)` d-orbitals and `(n-1)` f-orbitals
D. `(n-1)` d-orbitals and ns orbitals.

Answer

To solve the question regarding the inner transition elements and the subshells to which the added electrons go, we can break down the information step by step.

### Step-by-Step Solution:

1. **Understanding Inner Transition Elements**:
- Inner transition elements consist of two series: the lanthanides and the actinides.
- These elements are characterized by the filling of the f-orbitals.

2. **Identifying the Series**:
- **Lanthanoids**: These elements are found in the 6th period and involve the filling of the 4f subshell.
- **Actinoids**: These elements are found in the 7th period and involve the filling of the 5f subshell.

3. **Filling Order of Electrons**:
- In the case of lanthanides, the electrons are added to the 4f subshell.
- In the case of actinides, the electrons are added to the 5f subshell.

4. **Example of Curium**:
- Taking Curium (Cm) as an example, its electronic configuration is:
- Xenon core (Xe) + 4f¹ + 5d¹ + 6s².
- Here, the added electrons primarily occupy the 4f subshell.

5. **Conclusion**:
- Therefore, the inner transition elements are those in which the added electrons go to the f-orbitals, specifically the 4f for lanthanides and the 5f for actinides.

### Final Answer:
The inner transition elements are the elements in which the added electrons go to the f-orbitals, specifically the 4f subshell for lanthanides and the 5f subshell for actinides.

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