Th electronic configuration of Mn can be written as

Options

A. `[Ar] 4s^(2)`
B. `[Ar] 3d^(6), 4s^(2)`
C. `[Ar] 3d^(5), 4s^(1)`
D. `[Ar] 3d^(5), 4s^(2)`

Answer

To determine the electronic configuration of manganese (Mn), we follow these steps:

### Step 1: Identify the Atomic Number
The atomic number of manganese (Mn) is 25. This means that a neutral manganese atom has 25 electrons.

### Step 2: Write the Electron Configuration
We fill the electron orbitals according to the Aufbau principle, which states that electrons occupy the lowest energy orbitals first. The order of filling is as follows:

1. 1s
2. 2s
3. 2p
4. 3s
5. 3p
6. 4s
7. 3d
8. 4p

### Step 3: Fill the Orbitals
Now, we fill the orbitals with electrons:
- 1s can hold 2 electrons: **1s²**
- 2s can hold 2 electrons: **2s²**
- 2p can hold 6 electrons: **2p⁶**
- 3s can hold 2 electrons: **3s²**
- 3p can hold 6 electrons: **3p⁶**
- 4s can hold 2 electrons: **4s²**
- 3d can hold 10 electrons, but we only need to fill 5 for manganese: **3d⁵**

### Step 4: Combine the Configuration
Combining all the filled orbitals, we get the complete electron configuration for manganese:
- **1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁵**

### Step 5: Write the Noble Gas Notation
To simplify, we can use the noble gas notation. The electron configuration can be written as:
- **[Ar] 4s² 3d⁵**
Where [Ar] represents the electron configuration of argon (which is 1s² 2s² 2p⁶ 3s² 3p⁶).

### Final Answer
Thus, the electronic configuration of manganese (Mn) can be written as:
- **[Ar] 4s² 3d⁵**