The number of electrons present in 3d of `Cu^(o+)` is

Options

A. 20
B. 10
C. 16
D. 24

Answer

To determine the number of electrons present in the 3d subshell of the \( Cu^{+} \) ion, we will follow these steps:

### Step-by-Step Solution:

1. **Identify the Atomic Number of Copper**:
- The atomic number of copper (Cu) is 29. This means a neutral copper atom has 29 electrons.

2. **Write the Electronic Configuration of Neutral Copper**:
- The electronic configuration of copper can be written as:
\[ 1s^2 \, 2s^2 \, 2p^6 \, 3s^2 \, 3p^6 \, 3d^{10} \, 4s^1 \]
- Here, the 3d subshell is fully filled with 10 electrons, and there is one electron in the 4s subshell.

3. **Determine the Configuration of \( Cu^{+} \)**:
- The \( Cu^{+} \) ion means that one electron has been removed from the neutral copper atom. The electron is removed from the outermost shell first, which is the 4s subshell.
- Therefore, the electronic configuration of \( Cu^{+} \) becomes:
\[ 1s^2 \, 2s^2 \, 2p^6 \, 3s^2 \, 3p^6 \, 3d^{10} \, 4s^0 \]

4. **Count the Electrons in the 3d Subshell**:
- From the electronic configuration of \( Cu^{+} \), we can see that the 3d subshell still has 10 electrons.

5. **Conclusion**:
- The number of electrons present in the 3d subshell of \( Cu^{+} \) is **10**.

### Final Answer:
The number of electrons present in the 3d subshell of \( Cu^{+} \) is **10 electrons**.