The electronic configuration `1s^(2)2s^(2)2p^(6)3s^(1)3p^(3)3d^(2)` represents

Options

A. Ground state
B. 1st excited state
C. 2nd excited state
D. 3rd excited state

Answer

To determine what the electronic configuration `1s^(2)2s^(2)2p^(6)3s^(1)3p^(3)3d^(2)` represents, we will analyze the configuration step by step.

### Step 1: Count the total number of electrons
The first step is to count the total number of electrons in the given electronic configuration.

- For `1s^(2)`: 2 electrons
- For `2s^(2)`: 2 electrons
- For `2p^(6)`: 6 electrons
- For `3s^(1)`: 1 electron
- For `3p^(3)`: 3 electrons
- For `3d^(2)`: 2 electrons

Now, we sum these up:
\[ 2 + 2 + 6 + 1 + 3 + 2 = 16 \text{ electrons} \]

### Step 2: Identify the ground state configuration
The ground state configuration of an atom with 16 electrons (which corresponds to sulfur, S) would be:
\[ 1s^{2} 2s^{2} 2p^{6} 3s^{2} 3p^{4} \]
In this configuration, all electrons are in their lowest energy states.

### Step 3: Determine the excited states
To find the excited states, we need to see how electrons can be promoted from lower energy levels to higher ones.

- **First Excited State**: One electron from `3s` or `3p` can be promoted to `3d`. This would look like:
\[ 1s^{2} 2s^{2} 2p^{6} 3s^{2} 3p^{3} 3d^{1} \]

- **Second Excited State**: Two electrons can be promoted. One electron from `3s` and one from `3p` can be promoted to `3d`. This would look like:
\[ 1s^{2} 2s^{2} 2p^{6} 3s^{1} 3p^{3} 3d^{2} \]

### Step 4: Conclusion
The given electronic configuration `1s^(2)2s^(2)2p^(6)3s^(1)3p^(3)3d^(2)` matches the configuration for the **second excited state** of the atom.

### Final Answer:
The electronic configuration `1s^(2)2s^(2)2p^(6)3s^(1)3p^(3)3d^(2)` represents the **second excited state**.

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