The outermost shell electronic configuration `3d^(5), 4s^(2)` represents

Options

A. `Ca`
B. `Mn`
C. Te
D. `Zn`

Answer

To determine which element corresponds to the outermost shell electronic configuration of `3d^(5), 4s^(2)`, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Configuration**: The given outermost shell electronic configuration is `3d^(5), 4s^(2)`. This indicates that there are 5 electrons in the 3d subshell and 2 electrons in the 4s subshell.

2. **Determine the Total Number of Electrons**: The total number of electrons can be calculated by adding the electrons in both subshells:
\[ 5 \text{ (from } 3d) + 2 \text{ (from } 4s) = 7 \text{ electrons in the outermost shell.} \]

3. **Find the Atomic Number**: The total number of electrons corresponds to the atomic number of the element. The configuration `3d^(5), 4s^(2)` is characteristic of transition metals. The atomic number can be calculated as follows:
\[ 3d \text{ block starts filling after } 4s, \text{ so the total atomic number is } 25 \text{ (5 from } 3d + 2 from } 4s). \]

4. **Identify the Element**: The element with atomic number 25 is manganese (Mn). Its complete electron configuration is:
\[ \text{Mn: } [Ar] 4s^2 3d^5. \]

5. **Verify Other Options**:
- **Calcium (Ca)**: Atomic number 20, configuration is `[Ar] 4s^2`.
- **Tellurium (Te)**: Atomic number 52, configuration is `[Kr] 5s^2 4d^{10} 5p^4`.
- **Zinc (Zn)**: Atomic number 30, configuration is `[Ar] 4s^2 3d^{10}`.

6. **Conclusion**: The only element that matches the outermost shell electronic configuration `3d^(5), 4s^(2)` is manganese (Mn).

### Final Answer:
The outermost shell electronic configuration `3d^(5), 4s^(2)` represents manganese (Mn).